The Turk's Head is one of the most ancient of all decorative knots identified with the sailor, and also the most common.
Lever's "Sheet Anchor" (1808) states that a Turk's Head, "worked with a longline, will form a kind of Crown or Turban." This resemblance to a turban presumably is responsible for the name "Turk's Head."
The English sailors however refer to it as the True Lover's Know, because like true love there is no beginning and no end.
But whatever you decide to call it, there is no knot with a wider field of usefulness. From footholds, to napkin rings to bracelets, nothing is a functional as well as fancy.