1: Alexios Mavros -New Name (NP)

Submitter desires a masculine name.
Language/Culture (10th century (give or take) Byzantine) most important.

Alexios: 11th century Byzanting from "Personal Names of the Aristocracy in the roman era During the Later Byzantine Era - Masculine Given Names" from the SCA Heraldry website by ordas Xiphias

Mavros - ibid, Family Names Section gives a pattern of descriptive bynames meaning "Black".