However, as Trajan left the Persian Gulf for Babylon – where he intended to offer sacrifice to Alexander in the house where he had died in 323 BC[67] – a sudden outburst of Parthian resistance, led by a nephew of the Parthian king, Sanatruces, who had retained a cavalry force, possibly strengthened by the addition of Saka archers,[68] imperilled Roman positions in Mesopotamia and Armenia, something Trajan sought to deal with by forsaking direct Roman rule in Parthia proper, at least partially.[69]