What is "yasuke"

Yasuke, (variously rendered as 弥助 or 弥介, 彌助 or 彌介 in different sources.) (c. 1555/6-?) was a black (African, or of African origin) samurai of the Japanese hegemon and warlord Oda Nobunaga between 1581 and 1582. The name "Yasuke" was granted to him by Nobunaga, although why and when is unclear. His original name is not recorded in any known source, so it is unclear if Yasuke is a Japanese rendering of his previous name, or a wholly new name granted by his lord.'''