Charlemagne

Charlemagne (2 April 742/747/748 – 28 January 814), also known as Charles the Great or Charles I was the King of the Franks from 768, the King of Italy from 774, and from 800 the Emperor of the, which would eventually be succeeded by the Holy Roman Empire.

In 2012, Clay Kaczmarek included Charlemagne in one of the Glyphs inside the Animus for Desmond Miles to find.

Reference

 * Assassin's Creed II – Glyph #5: "Instruments of Power"