"the watch", medieval habit of 'two sleeps'

For millennia, humans slept in two separate chunks, waking up in the middle of the night for a period of activity known as "the watch".



BBC.COM
The forgotten medieval habit of 'two sleeps'

https://www.bbc.com/future/article/20220107-the-lost-medieval-habit-of-biphasic-sleep?ocid=fbfut