In 641 C.E. during the caliphate of Umar when 'Amr b Al 'Aas was the Governor of Egypt, an expedition under Uqba b Nafe' was undertaken against Nubia. The Nubians were very mobile, and as such no regular battle was fought. The operations consisted of skirmishes, haphazard engagements and hit-and-run raids. The Nubians were expert archers, and they caused considerable havoc among the ranks of the Muslims. Most of the Muslim soldiers lost their eyes. The war proved inconclusive, and the Muslim forces were Pulled out of Nubia without achieving any result.