Mahirn was an Andorian thaan or chan in the 23rd century.
He was a good friend Josh Pike and was the godfather of Josh's son Christopher Pike.
By 2254 Mahirn had risen to be an admiral in Starfleet, based at Starfleet Command. In that year the Klingon Kaaj made a fake message from Mahirn to Chris Pike informing him his father was ill to lure Pike away from his command the USS Enterprise to visit his father so that Kaaj might capture and kill him en route. Fortunately shortly after Pike departed Mahirn contacted the Enterprise for some reason, revealing the earlier transmission was a fake and alerting the Enterprise to the threat to their captain. (EV comic: "The Flat, Gold Forever")