Why You Wake Up at 3 a.m.: the Lost History of First and Second Sleep

12 October 202617 min read

It is 3:07 in the morning. No alarm, no noise, and yet you are wide awake, counting the hours until daylight and wondering whether something is wrong with you. For centuries, people in parts of Europe would have found this moment unremarkable: they spoke of a “first sleep” and a “second sleep”, with a waking hour between them. Here is the story of that forgotten rhythm, the honest scientific debate about it, what sleep science says about 3 a.m., and what you can do the next time you wake in the night.

Why do you wake up at 3 a.m.?

Waking in the middle of the night is far more common than it feels at the time. Most of us wake briefly several times a night and remember none of it by morning. If you fell asleep around eleven, by three you have slept for about four hours: much of your deep sleep is already behind you, lighter sleep and dreaming take up more of the night, and your body’s daily rhythm is beginning to turn towards morning. A noise, a full bladder, the wearing-off of an evening drink or a single worry can now wake you more easily. Once you are awake and look at the clock, the hour sticks in your memory, and the next night you notice it again.

That is the short answer. The long one is a stranger and more consoling story, and it begins with a child’s testimony in a London court.

First sleep and second sleep: a clue in a 1697 court record

The American historian A. Roger Ekirch was working through old English legal records, looking for anything that might show how ordinary people lived after dark. Among them he found the testimony of a nine-year-old girl, Jane Rowth, recorded in 1697. She told the court that her mother had woken after her “first sleep” and gone out into the night. Her mother never came back; she was later found dead.

Within that tragic account, one small detail caught Ekirch’s eye. A child had used the phrase “first sleep” without explaining it, as though everyone in the room knew exactly what it meant. If there was a first sleep, was there a second?

There was. Ekirch began searching, and the phrase kept surfacing: in diaries and letters, medical books and court records, prayer books, plays and poems. Over the years he gathered more than two thousand references in about a dozen languages. Some are more than six hundred years old. In Chaucer’s Canterbury Tales, the princess Canacee goes to bed soon after evening falls and wakes after her “first sleep”, while her companions sleep on until broad daylight. The trail runs back to Rome: Virgil describes the hour that ends the first sleep, when the chariot of Night has run only half its course.

The phrase turns up in darker places too. In 1595 the French witch-hunting judge Nicolas Remy listed the stages of the night: dusk, nightfall, the dark of night, the time of the first sleep, and finally the dead of night. Inquisition records from Montaillou, a mountain village in the Pyrenees, use “the hour of first sleep” in the early fourteenth century to mark a part of the night rather than a time on a clock.

From hundreds of such sources Ekirch drew a striking conclusion, first published in the American Historical Review in 2001 and later in his book At Day’s Close: across much of pre-industrial Europe, a night’s sleep commonly came in two parts. People went to bed around nine or ten, slept for several hours, woke some time after midnight, stayed awake for an hour or so, and then fell into a second sleep that lasted until dawn. The awakening was not, in itself, a sign that something was wrong. It was part of the shape of the night.

The hour between: what people did between the two sleeps

Doctors even gave advice about it. Medical books from the fifteenth to the eighteenth century told readers to lie on the right side during the first sleep and turn onto the left afterwards, guidance rooted in the medicine of their time rather than ours. And people found plenty to do with the waking interval, some of it holy and some of it not.

• Prayer. Prayer books included special prayers for the interval between the first and the second sleep. In darkness and silence, devotion had a quiet place of its own.
• Dreams. Waking straight out of a dream gave time to turn it over, remember its details and wonder whether it carried a meaning worth keeping.
• Work. Some got up to tend the fire, see to the children, brew, or finish tasks that would not wait for morning.
• Neighbours, and less welcome visitors. Records describe people visiting each other in the small hours, and thieves who raided orchards or carried off firewood while their owners slept.
• Intimacy. The sixteenth-century French physician Laurent Joubert attributed the fertility of labourers to lovemaking after the first sleep, when, he claimed, they had more enjoyment and did it better.

For people used to two sleeps, the waking interval did not have to feel like lost time. It could hold prayer, work or company, although neither privacy nor peace was guaranteed. In some English sources the interval even had a name of its own: the watch, or the watching.

A bell in the dark: monks and night prayer

Behind monastery walls, waking in the dark had a strict and formal place. Around the year 530, Saint Benedict wrote the rule that would shape monastic life in Western Europe for more than a thousand years. In winter, he wrote in chapter 8, the brothers were to rise at the eighth hour of the night, “so that they may sleep somewhat longer than half the night”. The night was divided into twelve hours from sunset to sunrise, so those hours changed length with the seasons and the eighth hour was not a fixed time on our clocks.

Sleep, then wake, then pray. The night office, known as Vigils or Matins, gathered the community long before dawn, and Benedict set aside the time after it for study by those who still needed to learn the psalms and readings.

The monks were not alone. Many traditions give the hours of darkness and the approach of dawn a special place:

• In Islam, the voluntary night prayer, tahajjud, is offered after sleeping and rising again, and the last third of the night is considered its best time.
• In Jewish tradition, some devout people rise after midnight for Tikkun Chatzot, a prayer of mourning for the destroyed Temple in Jerusalem.
• In Hindu tradition, brahma muhurta begins about an hour and thirty-six minutes before sunrise and is considered an auspicious time for meditation and study.

The experiment: fourteen hours of darkness a night

Faith can explain why people chose to rise in the night. But could long darkness change the shape of sleep by itself? In the early 1990s Thomas Wehr, a psychiatrist at the National Institute of Mental Health in the United States, set out to test exactly that. A small group of healthy young men spent about a month on an unusual schedule: fourteen hours of darkness every night, like a long winter night. No lamps, no reading, no screens. Just a dark room, a bed and a long stretch of night.

At first the volunteers slept for long stretches, probably making up for sleep they were short of when they arrived. By about the fourth week a different pattern had emerged. They slept for about four hours, woke and lay quietly awake for an hour or two, and then fell into a second sleep of roughly four more hours until morning. Nobody had told them to split their sleep. Wehr published the results in 1992 under a plain title: In short photoperiods, human sleep is biphasic.

There was one more intriguing detail. During the quiet waking interval, levels of prolactin, a hormone with many roles in the body, stayed raised. Accounts of the study compare that calm wakefulness to meditation, though no one has shown that the hormone causes the calm. What the experiment does show is that waking between two sleeps can be peaceful, very different from the anxious tossing and turning we usually call insomnia.

How artificial light changed the night

If two sleeps were once familiar, why did they disappear from memory? Part of Ekirch’s answer lies outside the bedroom, in streets that grew steadily brighter.

Before street lighting, city nights were far darker than ours. In 1667 Paris introduced a system of street lanterns, and public lighting gradually spread to other European cities. In 1807 the German-born promoter Frederick Winsor lit gas lamps along Pall Mall in London, and within a few decades gas light had spread through the towns of Britain. In 1879 Thomas Edison demonstrated a practical incandescent light bulb.

Evenings grew brighter and busier. Coffee houses stayed open late, work was increasingly ruled by the clock, and people went to bed later. In Ekirch’s reconstruction, the first sleep lengthened through the nineteenth century while the second shrank, until by the end of the century it was often little more than a doze before getting up. By the 1920s, references to first and second sleep had largely vanished from his sources. A single, unbroken night became the expectation, and a long waking interval became easy to see as a problem.

The scientific debate: did everyone sleep twice?

Before concluding that our ancestors simply slept better than we do, it is worth pausing. Researchers still disagree about how widespread two-part sleep really was.

The study of the Hadza, San and Tsimane matters because these communities live without electric light. If two sleeps were a universal human default, you might expect to find it there, and the researchers did not. Yet the Madagascar study found something much closer to Ekirch’s picture. In 2023 the researcher Niall Boyce re-examined the English sources and argued that the phrase “first sleep” does not always prove a customary two-part night; Ekirch replied in 2024, defending his interpretation. The question remains open.

So the careful conclusion is this: two-part sleep is well documented in pre-industrial Europe, though how common it was is debated, and it can emerge under long, dark nights in the laboratory. It is one possible shape of human sleep, not a hidden rule that every body is trying to follow. Human sleep is flexible: it bends to light and season, work and safety, culture and habit.

Why 3 a.m. feels so uncanny: the devil’s hour and the science

Folklore has its own answers about this hour. The witching hour. The devil’s hour. Modern ghost stories and horror films single out three in the morning as the moment something uncanny happens. In his 1968 film Hour of the Wolf, Ingmar Bergman described the hour before dawn as the time when sleep is deepest, nightmares are most real and the sleepless are haunted by their sharpest fears. It is a powerful image, but an artistic one: there is no evidence of anything supernatural about 3 a.m.

Ordinary sleep science explains a lot more:

• Sleep cycles. Sleep moves through cycles of roughly 90 minutes. Deep sleep is concentrated early in the night; later on there is less of it, and periods of dream-rich REM sleep grow longer. In lighter stages, a disturbance wakes you more easily.
• Remembering the waking. Brief awakenings are normal and usually forgotten. Longer ones give you time to notice the room, start thinking and remember being awake.
• The body clock. In the second half of the night the body’s daily rhythm begins to prepare for morning. Cortisol, a hormone involved in normal waking as well as in stress, generally rises in the early hours.
• Evening habits and the body. Alcohol can make it easier to fall asleep but tends to break up sleep later in the night. Stress and the need to go to the toilet can wake you too.

Then there is the part that makes night waking feel so bleak. In 2022 a team including researchers from the University of Arizona proposed what they called the “mind after midnight” hypothesis: being awake during the biological night may tilt us towards negative emotions and poorer judgement. Problems loom larger, worries feel more urgent and solutions seem further away. These are tendencies, not a fate. Expectation matters too. Someone used to two sleeps may have found the waking interval unremarkable. We often add a second worry on top of the first: I am awake, so something must be wrong with me. And that worry itself makes it harder to fall back asleep.

What to do when you wake up at 3 a.m.

Here is general guidance that sleep specialists often give. History offers perspective here, not a prescription: there is no need to recreate your ancestors’ nights.

1. Leave the clock and the phone alone. Checking the time feeds the worry, and bright screens and absorbing content make it harder to drift off again.
2. Do not force sleep. A brief, calm awakening is not a disaster. Let yourself rest in the dark, remembering that rest does not replace the sleep you need.
3. If you have been awake for a while, roughly twenty minutes, and feel restless, get up. Go to another room, keep the light low and do something calm until you feel sleepy, then go back to bed.
4. Borrow a quiet activity from the past. Say a prayer if you pray. Recall a dream. Write down a thought so that you do not have to hold it. Breathe slowly. There is no need to make the interval useful or meaningful, and no need to treat it as a failure.
5. Keep your mornings steady. Getting up at the same time after a broken night, instead of sleeping late to make up for it, helps keep the body clock regular.

This article is for curiosity and reflection and is not medical advice. If night waking troubles you, talk to a doctor.

When night waking needs a doctor

You are far from alone: in the survey by sleep researcher Maurice Ohayon, about a third of American adults reported waking during the night at least three nights a week. Most of these awakenings are harmless. But the history of first and second sleep does not cancel the need to check real symptoms. Talk to a doctor if:

• you have trouble sleeping at least three nights a week for three months or more, and it affects how you feel or function during the day;
• you are exhausted in the daytime, or fall asleep when you do not mean to;
• someone notices loud snoring, gasping or pauses in your breathing while you sleep, which can be signs of sleep apnoea;
• night waking comes with low mood, anxiety or racing thoughts that do not ease.

For long-term insomnia, medical guidelines recommend cognitive behavioural therapy for insomnia (CBT-I) as the first treatment to try. It is a structured, short programme that changes the habits and thoughts that keep sleeplessness going, and it is offered before sleeping pills.

The watching: a gentler way to see the night

Historical sources preserve the prayers, chores, conversations and thoughts of people who were awake in the middle of the night. For many of them it was simply part of the night. That does not mean they never suffered from sleeplessness, and it does not mean their story explains yours. But it offers a gentler question than “what is wrong with me?”: not only why you wake at three, but how to meet that moment calmly, while still taking your own health and your need for sleep seriously.

The night is long, and in human history it has held far more than sleep. If you find yourself awake in its quiet hour, remember that waking alone does not mean something is wrong with you. Sleep well, and if you wake, be gentle with yourself.

Questions

Sources

1. Ekirch, A. R. (2001). Sleep we have lost: pre-industrial slumber in the British Isles. American Historical Review, 106(2), 343–386. See also his book At Day’s Close: Night in Times Past (2005). doi.org
2. Wehr, T. A. (1992). In short photoperiods, human sleep is biphasic. Journal of Sleep Research, 1(2), 103–107. doi.org
3. Yetish, G., et al. (2015). Natural sleep and its seasonal variations in three pre-industrial societies. Current Biology, 25(21), 2862–2868. ncbi.nlm.nih.gov
4. Samson, D. R., et al. (2017). Segmented sleep in a nonelectric, small-scale agricultural society in Madagascar. American Journal of Human Biology, 29(4). doi.org
5. Boyce, N. (2023). Have we lost sleep? A reconsideration of segmented sleep in early modern England. Medical History, 67(2). ncbi.nlm.nih.gov
6. Ekirch, A. R. (2024). Reflections on “Have we lost sleep?”. Medical History. ncbi.nlm.nih.gov
7. Tubbs, A. S., et al. (2022). The mind after midnight: nocturnal wakefulness, behavioral dysregulation, and psychopathology. Frontiers in Network Physiology, 1. doi.org
8. Ohayon, M. M. (2008). Nocturnal awakenings and comorbid disorders in the American general population. Journal of Psychiatric Research, 43(1), 48–54. doi.org
9. Qaseem, A., et al. (2016). Management of chronic insomnia disorder in adults: a clinical practice guideline from the American College of Physicians. Annals of Internal Medicine, 165(2), 125–133. doi.org
10. The Rule of Saint Benedict, chapter 8: “The Divine Office at Night”. eriebenedictines.org

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