Until the close of the early modern era, Western Europeans on most evenings experienced two major intervals of sleep bridged by up to an hour or more of quiet wakefulness. In the absence of fuller descriptions, fragments in several languages in sources ranging from depositions and diaries to imaginative literature give clues to the essential features of this puzzling pattern of repose. The initial interval of slumber was usually referred to as ‘first sleep’, or, less often, ‘first nap’ or ‘dead sleep’. in French the term was premier sonneil or premier somme, in Italian, primo sonno or primo sono, and in Latin, primo somno or concubia nocte. The succeeding interval of sleep was called ‘second’ or ‘morning’ sleep, whereas the intervening period of wakefulness bore no name, other than the generic term ‘watch’ or ‘watching’. Alternatively, two texts refer to the time of ‘first waking’.
Both phases of sleep lasted roughly the same length of time, with individuals waking sometime after midnight before returning to rest. Not everyone, of course, slept according to the same timetable. The later at night that persons went to bed, the later they stirred after their initial sleep; or, if they retired past midnight, they might not awaken at all until dawn. […]
Men and women referred to both intervals as if the prospect of awakening in the middle of the night was common knowledge that required no elaboration. ‘At mid-night when thou wak’st from sleepe,’ described the Stuart poet George Wither; while in the view of John Locke, ‘That all men sleep by intervals’ was a normal feature of life […]. […]William Harrison in his Description of England (1557) referred to ‘the dull or dead of the night, which is midnight, when men be in their first or dead sleep.’
Customary usage confirms that ‘first sleep’ constituted a distinct period of time followed by an interval of wakefulness. Typically, descriptions recounted that an aroused individual had ‘had’, ‘taken’, or ‘gotten’ his or her ‘first sleep’.