Thomas Jefferson

Thomas Jefferson is considered to be a polyphasic sleeper. He slept only 2 hours a day.
Though, in letters to Doctor Vine Utley (1819), Thomas Jefferson writes about his sleep habits. We can conclude that his sleep was not very regular, he would go to sleep at different times (often late into the night), he would always devote at least 30 min. to creative reading before sleep, he would fall asleep later if the reading was of particular interest, and he would regularly wake up at sunrise.
Lifetime: 83