How waking up in the night is a relic of the ‘lost’ medieval habit of ‘two sleeps’ – which could be good for you… and your sex life

The notion that we should have around eight solid hours of shut-eye is something ingrained in nearly all of us.

Experts advise it, even if surveys show that millions of people fall well short of the target.

But, for those who do struggle to sleep, they might find solace, and some hope, in the knowledge that our medieval ancestors had very different bedtime habits.

As hundreds of written records reveal, the practice of ‘two sleeps’ – known as segmented, or biphasic sleep – was once the norm.

Rather than sleeping through the night, we used to spend a chunk of the small hours doing the likes of reading, praying, and – surprise surprise – having sex.

So could waking up in the middle of the night – something which becomes increasingly common as people age – be a hangover from that ‘lost’ habit?

Dr Kevin Morgan, a sleep expert at Loughborough University, says it is possible.

He told the Daily Mail: ‘You would be entitled on the basis of the evidence to suggest that amongst people who wake up in the middle of the night, maybe this is a residual echo of earlier propensities.’ 

But he adds: ‘It is heavily age dependent, just about anyone over 45 will start doing it. The older you get, the more you do it. The depth of sleep diminishes.’

The NHS recommends that adults get eight hours of sleep a night. 

But a survey by Nuffield Health in 2023 found that just 36 per cent of British adults get a ‘good’ night’s sleep – defined as 7.5 to 8.5 hours per night.

Of the 8,000 people surveyed, as many as 11 per cent of them said they sleep for just two to four hours nightly. 

Increasingly, people are turning to drugs prescribed by GPs to help them get to sleep. Many have crippling side effects. 

So what if we were to shun the medication and look back to what our forefathers did? 

The forgotten habit of ‘two sleeps’ was unearthed by historian Professor A. Roger Ekirch in Britain’s National Archives in the 1990s. 

He found records that demonstrated how people would sleep for a couple of hours from around 9pm and then be awake between 11 until 1, although the timings entirely depended on when people went to bed. 

Given that the bed was a good place to keep warm, getting into it sooner rather than later – especially in the bitterly cold winter nights – would have made sense. 

It was the cheapest and easiest way to keep the cold at bay.  

Professor Ekirch found that, as well as reading, praying and having sex, people would do chores such as sewing and chopping wood and even pay social visits while in the night-time waking period, which was known as ‘the watch’.

Professor Ekirch, the author of At Day’s Close: A History of Nighttime, went on to chart around 500 references to segmented sleeping in historical sources. 

They featured in works of fiction, diaries, medical textbooks, legal records and anthropological accounts.  

Geoffrey Chaucer wrote In The Squire’s Tale – one of the books in his Canterbury Tales – of a character who decided to go back to bed after her ‘firste sleep’. 

A doctor’s manual from the 16th century concluded that the best time for sex was in between the two sleeps, because it allowed men to ‘do it better’ and women to have ‘more enjoyment’.

Ballads also made reference to two sleeps. The classic English folk song Old Robin of Portingale spoke of, ‘”…And at the wakening of your first sleepe, You shall have a hot drink made, And at the wakening of your next sleepe, Your sorrows will have a slake…”

Much later, Charles Dickens would make mention of two sleeps in his 1840 novel Barnaby Rudge.

The famed author wrote: ‘He knew this, even in the horror with which he started from his first sleep, and threw up the window to dispel it by the presence of some object, beyond the room, which had not been, as it were, the witness of his dream.’ 

Chillingly, other references were much darker. Luke Atkinson of the East Riding of Yorkshire murdered someone between his sleeps one night. 

And there were mentions all across Europe, not just in Britain. The first sleep was known in France as the ‘premier somme’, and in Italy it was ‘primo sonno’.

Similarly, Professor Ekirch found evidence of the practice elsewhere across the world.  

But the expert was stunned when he came across a scientific study carried out a few years earlier by psychiatrist Thomas Wehr.

Wehr had, without realising the historical background, effectively re-created the old habit of segmented sleep. 

The expert, a sleep researcher at the National Institute of Mental Health in the U.S., put 15 young men into rooms and divided their day into 10 hours of light and 14 hours where they were left in the dark.

The aim was to mimic the light and dark pattern you would experience in early winter if you were not exposed to artificial light.

After four weeks, Wehr’s test subjects fell into a reliable pattern. 

They would sleep for four hours, then be awake for two hours from around midnight, and then sleep again for another four or five hours.

All the time they were asleep, the men wore electrodes that measured their brain activity.

Wehr found that the volunteers’ ‘first sleep’ was largely made up of deep sleep, during which the brain does things that include shifting memories from short-term into long-term storage.

The ‘admin’ makes space for memory the following day. This is why a lack of deep sleep can be seriously bad for your memory.

Wehr’s volunteers’ second period of sleep was usually lighter than the first, meaning they had less deep sleep and more of what is known as REM (rapid eye movement) sleep.

This refers to the period of sleep where most of your muscles (apart from your eye muscles) become paralysed. 

REM sleep is crucial too, because it is when our brain processes what we have experienced in the day.

So a lack of it can lead to stress and anxiety. 

Overall, Wehr’s volunteers slept for nearly nine hours a night, much longer than they usually would.

And blood tests carried out by Wehr on his subjects suggest that the period of being awake between the two sleeps may be highly relaxing too.

The brains of his volunteers were found to have increased levels of prolactin, a hormone which helps to lessen stress.

It explains the relaxed feeling people get after an orgasm.

Professor Ekirch found that references to the first and second sleep began to disappear in the late 18th century, when industrialisation was taking off. 

Both the introduction of wage labour and reliable lighting – first gas and then electric – helped push people to sleep in one solid block, as most of us do now. 

In his 2012 book The Slumbering Masses: Sleep, Medicine and Modern American Life, anthropologist Matthew Wolf-Meyer argued that our sleep habits now fit the schedule of capitalist society rather than what is natural.

Since the Industrial Revolution, we have had to wake up at regimented times to be at the workplace, and then stayed awake longer after darkness, consuming what has become a panoply of entertainment options. 

Eight hours of continuous sleep has become the advisable norm as we strive to fit into the demands of modern life.

But Professor Wolf-Meyer argued that the result has been a ‘culture of exhaustion’ that has spawned a mega-money industry selling us all manner of ‘cures’ to help us sleep. 

The expert concluded that we should embrace the variety and limits of sleep again. 

Dr Morgan cautiously echoes this view. He says: ‘Segmented sleep remains within the repertoire of human sleep capacity.

‘Whether or not the circumstances that fostered it in pre-industrial times can be recreated now is another matter. 

‘There is a point that flies off this, which is that segmented sleep tells us that sleep is incredibly plastic, it is adaptable.

‘If people feel they are sleeping inadequately, then segmented sleep tells us the option of making our sleep longer is ours, it is within our gift.’

However, Dr Morgan is insistent that segmented sleep is not some kind of fix-all. Everyone is different. 

‘There is an assumption we abuse our sleep and that we need more sleep now,’ he adds. 

‘The idea that if we just reverted to some early medieval bucolic past we would be better off doesn’t match the world we are living in.

‘If the question is would it be appropriate to slip back into segmented sleep, I would say if we accept it is a human capacity to do this, then that capacity still exists in the 60 odd million people who live in the UK.

‘Human nature being what it is, I bet there are some people who already do this. I bet some of them are pushing middle age and beyond.

‘As a general rule, is segmented sleep a useful lifestyle option? The evidence would suggest yes, perhaps for those whose habits embrace pre-industrial wake patterns. 

‘But if you have to go to the office, I wouldn’t recommend it.’