There was a mild flurry about a year ago around the release of Evening’s Empire, by Craig Koslofsky. Like the 2005 book by Roger Ekirch, At Day’s Close: Night in Times Past, Koslofsky’s book examines pre-electric lighting patterns of behaviour at night, including sleep patterns. The BBC has a nice article on the two here. Both Koslofsky and Ekirch assert that until the 19th century, humans typically slept in two blocks of about 4 hours each, and scientists confirm this natural tendency.
Last year, between December and March, I had the luck to test this theory, and once again, it seems I will be sleeping old school, in blocks of time. Unfortunately, these blocks of time are often 2 hours and not 4 hours, as the scientists and historians claim we need. User testing of one shows me that 2 hour sleep blocks (or 4 hours followed by 2 hours) are inadequate and I may be near-hallucinatory by March, just as I was last year.
When doing living history, its always better not to skimp on resources.