The medieval habit of 'two sleeps'

Nearly 300 years later, in the early 1990s, the historian Roger Ekirch walked through the arched entranceway to the Public Record Office in London – an imposing gothic building that housed the UK's National Archives from 1838 until 2003. There, among the endless rows of ancient vellum papers and manuscripts, he found Jane's testimony. And something about it struck him as odd.

Originally, Ekirch had been researching a book about the history of night-time, and at the time he had been looking through records that spanned the era between the early Middle Ages and the Industrial Revolution. He was dreading writing the chapter on sleep, thinking that it was not only a universal necessity – but a biological constant. He was sceptical that he'd find anything new... More here.

I sleep through the night once or twice a month, all other nights are broken into at least 2 sleeps. It has always been this way for me.