Tavis Olier

Tavis Olier, better known as the "Black Cross", was a Templar agent active during the late 18th century/early 19th century.

The inquisitor of the Inner Sanctum like all the Black Crosses before him, Olier travelled all around the world to keep an eye on the Grand Masters of the various Rites, to verify that they stayed in line with the Templar Code and if necessary to eradicate any corrupted Templars he could find. His secondary mission was also to track Pieces of Eden for the Inner Sanctum.

Sometimes before 1805, Olier was sent to infiltrate the palace of Sultan Selim III to investigate about the Koh-i-Noor but was captured and imprisoned. Believed dead, a new Black Cross was appointed, Solomon Bolden, who eventually discovered clues about Tavis' survival and presence in Tripoli. However, Bolden was killed by the Sultan's men and his travel companion, Jan van der Graff, whom Selim believed to be another Templar infiltrator, was put in the cell of Tavier. The Black Cross then took Graff as his student.

Reference

 * Assassin's Creed: Templars