How the ancients slept

No, this is not a blog post about H. P. Lovecraft or his work. It is about how people used to sleep, a story I picked up from the BBC. It is a story that showed me how much I take for granted certain things, like our way of sleeping.
Historian Roger Ekirch from Virginia Tech has shown with sources as far back as Homer that people used to sleep in two periods each night, with a period of activity or contemplation in between. Many sources refer to this as the first and second sleep, and it appear to have been perfectly ordinary to people before the enlightenment.
In a way it makes sense, at a time when artificial light was expensive you went to bed at dusk slept for a while, got up to do some chores, talk to your family, or pray in the middle of the night, after a while you went back to sleep and slept until morning.
There is also empirical research regarding sleeping patterns that cooperate that this divided sleep is natural to people. There are experiments that have been performed by Thomas Wehr and also anthropological studies of populations living without artificial light. It is also stated that this way of sleeping can be found in other mammals.
The artificial light we now take for granted has a rather short history, Paris became the first city with street lights in 1667. (I wonder if that might have anything to do with Paris being know as La Ville-Lumière) It became easier and easier for people to occupy themselves after dusk and the industrial revolution made sure that even sleeping had to be done efficiently without brakes.
This research give ample fodder for speculation. Are people who experiences problems sleeping just trying to sleep the way nature intended for them? Some people have been reported to sleep only a few hours each night, usually you here this about very productive people, might they have slept at other times in addition to their reported nightly sleep? And how screwed up is my sleep pattern if this is the way we are supposed to sleep?
For people who wants to learn more there is a book by Ekirch: At Day's Close: Night in Times Past I am considering getting it, but I already have a few books.
Other sources are:

THOMAS A. WEHR In short photoperiods, human sleep is biphasic, Journal of Sleep Research, 1992 (1) 103-107
Roger A. Ekirch Sleep We Have Lost: Pre-industrial Slumber in the British Isles, American Historical Review, CV, no.2 (April 2001), 343-387