For Centuries, Waking Up at 2AM Wasn’t Insomnia. It Was Called Your “First Sleep” Ending

People used to wake in the dead of night on purpose. They’d add wood to the fire, read, reflect on their dreams, visit neighbors, or spend time with whoever was next to them. Nobody treated it as a problem.

Historical and biological evidence suggests that waking up in the middle of the night is not a malfunction. It is a return to form.For the vast majority of human history, sleep was not a single, unbroken eight-hour block. It was a two-act play with a rich, productive intermission.

The Two Sleeps of Our Ancestors

Before the Industrial Revolution, the human night was structured around “segmented” or “biphasic” sleep. People fell asleep in two distinct intervals, separated by a period of quiet wakefulness.

The first interval, often called “first sleep” or “dead sleep,” began shortly after dusk. It lasted roughly four hours, ending around midnight. At that point, people would wake up naturally.

This middle stretch of the night, lasting anywhere from one to three hours, was known as “the watch.” Far from a period of frustrated tossing and turning, the watch was a cherished, normal part of the daily routine. During these hours, people did not worry about insomnia because the concept did not exist in the way we define it today. Instead, they used the time productively or reflectively:

Socializing and Intimacy: Couples would talk, share dreams, or make love. In fact, medical manuals from the 16th century noted that the period after first sleep was the best time for conception, as couples were well-rested and relaxed.

• Household Chores: People used the quiet hours to tend to the fire, brew beer, or perform minor domestic tasks that required little light.
• Intellectual and Spiritual Pursuits: Writers, scholars, and artists found the stillness of the watch ideal for deep concentration. Many used the time to pray, meditate, or write down the vivid dreams they had just emerged from.
• Community Life: Neighbors would sometimes slip out of their homes to visit one another, share a late-night drink, or even commit petty thefts under the cover of a quiet town.

This pattern was so deeply ingrained in the global psyche that it was rarely questioned. Historian A. Roger Ekirch, who spent decades researching the history of sleep, has uncovered more than 500 references to segmented sleep across ancient, medieval, and early-modern documents. It appears in legal depositions, diaries, medical guides, and literature, including Homer’s Odyssey and the works of Geoffrey Chaucer.

How Technology Rewired Our Nights

If segmented sleep was the default human experience for thousands of years, why does it feel so foreign to us now?

The answer lies in the invention and spread of artificial lighting.

Before the late 19th century, the night was dark, expensive to illuminate, and occasionally dangerous. Wax candles and oil lamps were luxuries. When the sun went down, humans had little choice but to retreat indoors and head to bed. This created a massive, 12-to-14-hour window of darkness. Because humans only need about eight hours of sleep, this wide window naturally split into two blocks with a gap in the middle.

Street lighting and domestic electricity changed everything. Suddenly, the night became an extension of the day. Cities stayed awake, factories ran night shifts, and social lives stretched long past sunset.

As we compressed our natural window of rest to fit a rigid, industrialized schedule, we forced our bodies to pack all of our sleep into one single, uninterrupted block. By the early 20th century, the memory of “first” and “second” sleep had vanished from the public consciousness, replaced by a new, modern expectation: sleep through the night, or something is wrong with you.

The Biological Memory of the Dark

Our culture may have forgotten segmented sleep, but our biology has not.

In 1992, chronobiologist Thomas Wehr conducted a landmark study to see what happens when humans are stripped of modern lighting schedules. He placed a group of healthy men in an environment with 14 hours of darkness every day for a month, mimicking the natural conditions of a pre-industrial winter.

At first, the subjects slept in long, erratic chunks as they caught up on their modern sleep debt. But by the fourth week, a pattern emerged.

The men naturally shifted to a biphasic sleep schedule. They slept for about four hours, woke up for two to three hours of quiet wakefulness, and then slept for another four hours. They had successfully reprogrammed their bodies back to the ancestral rhythm.

Even more fascinating was what happened to their brain chemistry during the middle waking gap. Wehr discovered that during this period, the brain produces high levels of prolactin.

Prolactin is the same pituitary hormone responsible for the calm, dreamy, and meditative state we feel after intimacy or during quiet reflection.

It is a hormone that reduces stress and induces a state of peaceful clarity. This explains why our ancestors did not panic when they woke up at midnight; their brain chemistry was actively keeping them calm, creative, and relaxed.

Reclaiming the Night

Today, we live in a world designed for the single-sleep model. Our jobs, schools, and social structures require us to be awake and productive during a single, continuous block of daylight, and asleep during a single block of darkness.

Because of this, trying to force a true biphasic schedule into a modern life is incredibly difficult for most people. However, understanding this history changes how we view our struggles with sleep.

If you wake up at 2 AM and find yourself unable to drift back off immediately, you are not necessarily suffering from clinical insomnia. You are likely just experiencing a momentary slip in your modern conditioning. Your body is reaching back through centuries of evolutionary history, attempting to run an older, deeply human program.

Instead of fighting the dark, staring at your clock, and generating anxiety, there is power in leaning into the lull. Turn on a dim, warm light. Read a chapter of a book, write down your thoughts, or simply sit in the quiet.

Your ancestors called this “the watch.” It was never meant to be feared, it was meant to be lived.