They Woke at Midnight on Purpose. Nobody Called It Insomnia.
Body · The Britannica Series, Vol. 13 · 10 min read · what segmented sleep was, why page one argues about it, and what to do with the hour you are awake at 3 a.m.
Based on the published work of A. Roger Ekirch, PhD, University Distinguished Professor of History at Virginia Tech, whose book At Day’s Close: Night in Times Past and whose papers in the American Historical Review and Sleep recovered the “first sleep” and “second sleep” from more than two thousand historical sources. Virginia Tech faculty page · his segmented sleep research site · on X · Britannica
For most of recorded history, waking in the middle of the night was not a symptom. It had a name, a purpose and a second half, and the fear you feel at 3 a.m. is younger than the waking itself.
The short answer: segmented sleep is sleep taken in two blocks, a “first sleep” and a “second sleep”, separated by an hour or more of quiet wakefulness. The historian Roger Ekirch found more than two thousand references to it in diaries, court records, medical books and literature, and argues it was the normal pattern in preindustrial Western Europe until artificial light and industrial schedules compressed it into one block by the late nineteenth century.¹ ² In 1992 a psychiatrist at the National Institute of Mental Health gave volunteers fourteen hours of darkness a night and watched a similar two-part pattern appear.³ In 2015 a UCLA team measured sleep in three societies without electricity and did not find it.⁴ The fair reading: two-part sleep is something human sleep can do, especially on long dark nights, and does only some of the time. Either way, the waking alone was never treated as an illness. The alarm about it is modern, and it is the part that treatment now targets.⁵
The ceiling. Then the clock, which you should not have looked at: 3:07. You went to bed at eleven, tired in the good way, and now you are wide awake with a clear head and a list. The house is quiet. Somewhere in the first minute a second thought arrives, the one that does the real damage: something is wrong with me. Everyone else sleeps through. You used to. Now you lie very still and calculate how many hours are left if you fall asleep right now, and then right now, and then right now.
Here is a question worth asking before the calculation starts. What is segmented sleep, and were people once expected to wake in the middle of the night? Page one will answer with confidence and in two opposite directions. One set of articles says our ancestors all slept in two shifts, so your 3 a.m. waking is ancient and natural. Another says a study of hunter-gatherers found no such thing, so the two-sleep story is a myth. Both are partly right, and the part they leave out is the useful one.
This is a reading of published history, sleep research and one clinical guideline. We are not historians or clinicians; the findings belong to the researchers and institutions named and linked below, and the plain-English version is ours.
The skim version
- 2,000+ references. Ekirch’s count of historical mentions of a “first sleep” and “second sleep”, from Roman times to the early twentieth century.²
- 2001. His paper “Sleep We Have Lost” appears in the American Historical Review.¹
- 1992. Thomas Wehr at the NIMH gives volunteers 14 hours of darkness a night; their sleep splits into two bouts with quiet waking between.³
- 2015. Jerome Siegel’s team tracks 94 adults in three preindustrial societies for 1,165 days and finds they rarely woke for long periods.⁴
- 2008. A study of 3,045 women aged 42 to 52 finds trouble staying asleep becomes more likely through the menopausal transition.⁶
- The honest part: the historical evidence is written testimony, not measurement, and the lab study was eight men. Nobody has measured sleep in a Victorian bedroom, so “natural” here is an argument, not a finding.
In this article: The 19th century: the last of the first sleep · The 20th century: one block, and a new diagnosis · The 21st century: what segmented sleep means now · Three centuries of 3 a.m. · Questions people ask
The 19th century: the last of the first sleep
Start with how ordinary it was. Ekirch, a historian of early America who came to the subject while researching the history of night, kept finding the same phrase in sources that had no reason to explain it: people went to bed, had their “first sleep”, woke, and later fell into their “second sleep”.² Nobody defined the terms. They did not need to, the way nobody today explains “lunch”.
He found it in novels, letters, medical texts, court records and periodicals, reaching back to a translation of Apuleius: “When midnight came, that I had slept my first sleepe, I awaked.”² The interval between the two had a name of its own in some places, “the watch”, and it was used. People prayed, reflected on their dreams, talked to whoever was beside them, made love, tended the fire, checked on children and animals, and in some households got on with work.² For a woman running a preindustrial house, the quiet hour after midnight was available time.
Ekirch put it this way: “No other period afforded such a secluded interval of darkness in which to absorb fresh visions of solace, spirituality, and self-revelation.”⁷
Then it went. Over the nineteenth century, as street lighting and domestic lighting spread and working days were set by the factory and the office rather than the sun, bedtimes moved later and the night shortened. In Ekirch’s words, sleep “that had been ‘segmented,’ with a provenance as old as humankind, gradually, by the late nineteenth century, became compressed and consolidated.”⁷ By 1900 the phrase “first sleep” had largely dropped out of use, which is why it reads as strange to us now.²
The 20th century: one block, and a new diagnosis
Once one continuous block became normal, waking in the middle of it became abnormal by definition. Encyclopaedia Britannica defines insomnia simply as “the inability to sleep adequately,” and lists stress, apnea and circulatory, brain and other disorders among its causes.⁸ What a nineteenth-century farmer’s wife would have called the watch, a twentieth-century doctor could reasonably call sleep maintenance insomnia. Same hour, different label, very different feeling.
The strongest modern clue that the old pattern was more than folklore came from a laboratory. In the early 1990s Thomas Wehr, a psychiatrist and later scientist emeritus at the National Institute of Mental Health, changed the light schedule of healthy volunteers from the usual sixteen hours of light and eight of dark to ten hours of light and fourteen of dark, the length of a winter night before electric light.³ After the first weeks, when they slept long to pay back what they owed, their sleep reorganised into two bouts separated by a spell of quiet, calm wakefulness, the shape Ekirch had been reading about in court records.³ ⁹
That experiment is often quoted as proof. It is better read as a demonstration: given long enough nights and nothing to do, human sleep can fall into two halves. What would happen with a 6 a.m. alarm is another question, and there were only eight participants, all of them men.⁹
If the 3 a.m. waking is not really about sleep, if it is the one hour your mind finally gets to itself and fills it with the list, that is worth ten quiet minutes in daylight to look at properly. Start here.
The 21st century: what segmented sleep means now
Then the counterweight. In 2015 Jerome Siegel, Professor of Psychiatry at UCLA’s Semel Institute for Neuroscience and Human Behavior, published a study in Current Biology that tracked 94 adults among the Hadza of Tanzania, the San of Namibia and the Tsimane of Bolivia, three societies without electricity, over 1,165 days in total.⁴ They slept on average about six and a half hours, and they rarely woke for long periods during the night.⁴ The two-shift pattern did not show up.
Two further findings from the same study matter more for you than the argument does. They tended to wake as the night’s temperature reached its lowest point, which gave them consistent wake times.⁴ And insomnia was so rare that the San and Tsimane had no word for it.⁴ Siegel’s summary: “The argument has always been that modern life has reduced our sleep time below the amount our ancestors got, but our data indicates that this is a myth.”⁴
Historians have pushed back too. In 2023 Niall Boyce of Birkbeck, University of London, re-read many of Ekirch’s sources in Medical History and argued that “first sleep” had several meanings and that a number of the texts describe prisoners, soldiers or the sick rather than ordinary households.¹¹ He does not deny that segmented sleep happened. He argues it may have been less routine than the story now told about it.¹¹
So which is it? Probably both, in different places. Ekirch’s sources describe northern Europe, with long winter nights and early bedtimes; Siegel’s societies live near the equator, with nights of roughly twelve hours all year and people going to bed well after dark. Two-part sleep looks like something sleep does when the night is long. What both bodies of evidence agree on is the more useful fact. Waking in the night was not, in either world, something people panicked about.
There is one more piece of evidence, and it is about you specifically. The Study of Women’s Health Across the Nation followed 3,045 American women aged 42 to 52 for seven years. Howard M. Kravitz of Rush University Medical Center and colleagues found that the odds of difficulty falling asleep and staying asleep rose through the menopausal transition, and that more frequent hot flashes and falling estradiol were each linked to higher odds.⁶ So if you slept through the night at forty and do not at fifty-one, that is not imagined, and part of it may be hormonal rather than historical.
What the research found
Waking in the night is old. The fear of it arrived much later. Written sources describe a first and second sleep across centuries of European life,¹ ² and a long-night laboratory schedule can reproduce a similar pattern.³ Preindustrial societies near the equator did not show it, and they barely knew insomnia either.⁴
What has been tested: the treatment with the strongest recommendation for chronic insomnia is cognitive behavioural therapy, ahead of any sleeping pill, and it works partly by changing how you respond to being awake.⁵
The limitation: the historical case rests on what people wrote, not on measured sleep, and literate writers are not a random sample. A 2023 re-reading of those sources argues many describe unusual nights rather than ordinary ones.¹¹ Wehr’s study had eight men and Siegel’s had 94 adults in three societies. None of these studies tested whether treating 3 a.m. waking as normal helps a woman in midlife sleep better; that is our inference from the treatment evidence, not a finding.
The source for this piece
A. Roger Ekirch, PhD
University Distinguished Professor of History, Virginia Tech. A historian of early America and of night itself, and a Guggenheim Fellow. His 2005 book At Day’s Close: Night in Times Past (W. W. Norton) brought the first and second sleep back into print. He is a historian, not a sleep physician.
What we read: his research summary on segmented sleep, his 2001 American Historical Review paper and his published comments on insomnia, alongside the laboratory, field and clinical research below.¹ ² ⁷
Where to follow his work: Virginia Tech · his research site · Virginia Tech News on his appointment
Three centuries of 3 a.m.
| 19th century | 20th century | 21st century | |
|---|---|---|---|
| What the night looked like | First sleep, the watch, second sleep, fading by 1900² | One block, eight hours the ideal | One block, measured by a watch on your wrist |
| What waking at 3 a.m. was called | Between sleeps¹ | Insomnia⁸ | A “bad sleep score” |
| What she did with the hour | Prayed, talked, tended the fire, worked² | Lay still and worried | Checked the phone |
| What she was told | Advice in medical texts, not a diagnosis¹ ² | Take something | CBT for insomnia, first line⁵ |
| What we know now | Written evidence only¹ | Long nights can split sleep³ | Midlife raises the odds of waking⁶ |
Who else has measured this
Jerome Siegel, PhD, Professor of Psychiatry at the UCLA Semel Institute for Neuroscience and Human Behavior, led the 2015 study of sleep in the Hadza, San and Tsimane, the strongest evidence against two-shift sleep as a universal human pattern.⁴
Semel Institute profile · the study, at UCLA Newsroom · Google Scholar
Thomas A. Wehr, MD, scientist emeritus and former chief of the Clinical Psychobiology Branch at the National Institute of Mental Health, ran the 1992 long-night experiment in which biphasic sleep appeared under fourteen hours of darkness.³ ⁹
the 1992 paper, PubMed · Journal of Sleep Research · reference entry
Howard M. Kravitz, DO, MPH, of Rush University Medical Center, was lead author of the SWAN analysis of sleep across the menopausal transition in 3,045 women.⁶
Rush University faculty page · the paper, in Sleep · ResearchGate
The late Jack D. Edinger, PhD, professor in the sleep medicine section at National Jewish Health in Denver, chaired the American Academy of Sleep Medicine guideline that made cognitive behavioural therapy the strongly recommended treatment for chronic insomnia.⁵
AASM announcement · the guideline · Sleep Review obituary
Niall Boyce, PhD, of the Department of English, Theatre and Creative Writing at Birkbeck, University of London, published the 2023 reconsideration of the historical evidence for segmented sleep in early modern England.¹¹
the paper, in Medical History · Birkbeck, University of London
Encyclopaedia Britannica supplies the two anchors: sleep itself and the modern definition of insomnia.⁸ ¹⁰
Britannica on sleep · Britannica on insomnia
They woke at midnight too. They just called it the watch.
What this actually changes
It takes the second thought away. Waking at 3 a.m. is weak evidence that you have broken something that works for everyone else. For centuries it was a normal feature of a long night, and people used the hour rather than fighting it. Ekirch has described the modern problem precisely: “Many patients, I have been told, regard themselves as abnormal, which only heightens their anxiety, thereby accentuating their inability to sleep.”⁷
That is the loop worth breaking. The waking itself is often brief and harmless. What keeps you up is the alarm about it: the clock-checking, the arithmetic, the verdict on yourself. Cognitive behavioural therapy for insomnia targets exactly that response, and it is the first-line treatment for a reason.⁵ What it asks is simple and hard: stop treating an awake hour as an emergency.
The one move
Tonight, turn the clock to face the wall, or put the phone in another room. If you wake, you will have no idea whether it is 2:40 or 4:15. Good. No arithmetic.
If you are still awake after what feels like twenty minutes, get up and do something quiet in low light, the way people did during the watch: a few pages of a paper book, a cup of something warm, folding one basket of laundry. Go back to bed when you feel sleepy. This is a standard part of insomnia treatment, and we have written about why getting up works better than lying there.
Segmented sleep: questions people ask
What is segmented sleep?
Sleep taken in two main blocks with a period of wakefulness between them, historically called the “first sleep” and “second sleep”. Historian Roger Ekirch documented it in more than two thousand sources and argues it was common in preindustrial Western Europe before artificial light and industrial schedules consolidated sleep into one block.¹ ²
Is waking up at 3 a.m. normal?
Brief waking during the night is common at any age and becomes more likely in midlife; a study of 3,045 women found the odds of trouble staying asleep rose through the menopausal transition.⁶ It becomes a problem when you cannot get back to sleep, it happens most nights, and you feel the effects during the day.
Did people in the Middle Ages really sleep twice a night?
Written sources describe it widely in medieval and early modern Europe.¹ ² Measurements are harder: a 1992 laboratory study produced a similar pattern under long nights,³ while a 2015 study of three preindustrial societies near the equator did not find it.⁴ The most careful reading is that it was common where nights were long, not universal.
Should I try to sleep in two shifts on purpose?
We would not suggest it if you have a morning job, and there is no trial showing it improves health today. The more useful lesson from history is about attitude: an awake hour in the night can be allowed to be just an hour.
When is waking in the night worth seeing a doctor about?
When it happens at least three nights a week for three months and affects your days, or comes with drenching night sweats, loud snoring or gasping, needing to pass urine several times, restless legs, or low mood most days. Perimenopause, sleep apnea, thyroid problems and depression can all show up as night waking, and all can be checked. A useful sentence to bring: “I wake most nights around [time] and cannot get back to sleep, and it has been like this for [how long].”
Ten quiet minutes, when you want them
The one move
Clock to the wall tonight. If you wake, no arithmetic. If it drags, get up, low light, go back when sleepy.
And if the thing waiting for you at 3 a.m. is always the same list, the one there is no room for in daylight, that list is worth ten quiet minutes of its own. No advice, no programme, just the document. Start here.
They had a word for the hour you keep losing. You are allowed to have it back.
Related reading: why the meeting comes back at 3 a.m., what night sweats have to do with the waking, and why lying there teaches the bed the wrong thing.
On the sources. This volume rests on one historian’s published research and interview comments, one historian’s published critique of it, one laboratory study, one field study in three societies, one longitudinal cohort study of midlife women, one clinical practice guideline and two encyclopaedia entries. The historical evidence is written testimony rather than measurement. We name the page-one claims we are weighing and do not link them, because a link is a recommendation.
Disclosure
This article is informational and reflects published history and research. It is not medical advice, and it is not a substitute for seeing a doctor about persistent sleep problems.
We are not historians or clinicians. We read published research and translate it into plain English. The findings belong to the researchers and institutions named and linked above.
Blue Leaf Journal has no affiliation with, and no endorsement from, Professor A. Roger Ekirch, Virginia Tech, Professor Jerome Siegel, UCLA, Dr Thomas Wehr, the National Institute of Mental Health, Dr Howard M. Kravitz, Rush University Medical Center, the Study of Women’s Health Across the Nation, Dr Niall Boyce, Birkbeck, University of London, National Jewish Health, the American Academy of Sleep Medicine or Encyclopaedia Britannica. Naming their work is citation, not partnership.
No commercial relationship. Nobody named above paid for or was paid for this coverage, and there are no affiliate links in this article.
Every figure was checked against the source listed below on 27 September 2026. If you find an error or a broken link, write to editor@blueleafjournal.com and we will correct it and date the correction.
References
1. Ekirch, A. R. “Sleep We Have Lost: Pre-industrial Slumber in the British Isles.” The American Historical Review 106(2), 2001, p. 343 onward. See also Ekirch, A. R., At Day’s Close: Night in Times Past, W. W. Norton, 2005.
2. Ekirch, A. R. “Segmented Sleep.” Research summary, Virginia Tech. Source for the count of more than 2,000 references, the activities of the interval and the late nineteenth-century decline.
3. Wehr, T. A. “In short photoperiods, human sleep is biphasic.” Journal of Sleep Research, 1992. PubMed record.
4. Yetish, G., Kaplan, H., Gurven, M., et al., with Siegel, J. M. “Natural sleep and its seasonal variations in three pre-industrial societies.” Current Biology, October 2015. Summarised by UCLA Newsroom, source for the sample, durations, temperature and insomnia findings and the Siegel quotation.
5. Edinger, J. D., et al. “Behavioral and psychological treatments for chronic insomnia disorder in adults: an American Academy of Sleep Medicine clinical practice guideline.” Journal of Clinical Sleep Medicine, 2021. AASM announcement, December 2020.
6. Kravitz, H. M., Zhao, X., Bromberger, J. T., et al. “Sleep Disturbance During the Menopausal Transition in a Multi-Ethnic Community Sample of Women.” Sleep 31(7), 2008, pp. 979 to 990.
7. “My Q and A With Roger Ekirch on the Way We Sleep, and How It’s Changed Over the Centuries.” HuffPost. Source for the three Ekirch quotations.
8. “Insomnia.” Encyclopaedia Britannica.
9. “Ancient Sleep in Modern Times.” Scientific American. Source for the eight participants and the shape of the bouts.
10. “Sleep.” Encyclopaedia Britannica.
11. Boyce, N. “Have we lost sleep? A reconsideration of segmented sleep in early modern England.” Medical History, 2023.
About the researcher
A. Roger Ekirch is University Distinguished Professor of History at Virginia Tech and a Guggenheim Fellow. His books include At Day’s Close: Night in Times Past and Birthright (both W. W. Norton), American Sanctuary (Pantheon) and Bound for America (Oxford University Press). His sleep research has appeared in the American Historical Review and in Sleep.
Virginia Tech faculty page · research site · At Day’s Close, at W. W. Norton · ResearchGate · X
His PhD is in history. He is a historian of night and sleep, not a medical doctor, and nothing here is clinical advice.
Written by Tomasz Nowak for Blue Leaf Journal.
