ANTINOUS – the most faithful companion of the ‘ancient’ Emperor Hadrian and ANTONINUS, twin-brother of the ‘ancient’ Roman Emperor Commodus – I’ve already covered here.
SERGIY – a Christian Arian, who baptised Prophet Mohammed with water according to the Christian ordinance (I can find no reference right now)
ANTHONY OF KIEV (Anthony of the Caves)
HAMLET SENIOR (KING HAMLET), HAMLET JUNIOR, DUNCAN and BANQUO plus MACDUFF have all been covered here before :o)