Why is the word late used to describe the recently deceased?

To prefix a person’s name with “the late” certainly signifies that he or she
is dead, although you would be correct in using it only with the name of
someone who had died within the past twenty years. Its use began with
medieval rulers, whose first name often had been passed down through
generations of males. To avoid confusion with the living monarch, i.e.,
James II, his deceased father would be referred to as “the late King James.”