Cain

Cain and Abel, according to the Bible, were the first two sons of Adam and Eve (Cain being the eldest). Cain would go on to kill Abel who, according to the Bible had pleased God with his offering while Cain had not. A mark was then put upon Cain which later became the symbol of the Knights Templar. Subject 16 confirmed through a glyph sequence that Cain did in fact exist, and murdered someone (probably Abel) to get ahold of a Piece of Eden. Given Cain's 'mark' is the same symbol as that of the Knights Templar, it is implied that Cain was the first Knights Templar, and established them with the goal of gaining control of the Piece's of Eden. How long ago this was is unknown, though if the Bible is to be believed, he and Abel where the sons of Adam and Eve, placing the event of Abels murder one generation after them.