Each of these authors (excepting Imhotep, none of whose works survive) including Ptahemdjehuty,[5] can be attested as authors of various works from the Middle Kingdom. Many of the earliest Sebayt claim to have been written in the third millennium BCE, during the Old Kingdom, but it is now generally agreed that they were actually composed later, beginning in the Middle Kingdom (c.1991-1786 BCE). This fictitious attribution to authors of a more distant past was perhaps intended to give the texts greater authority.