Wasan Sagad was a negus or king of Abyssinia ruling in the mid 7th century. The second son of King Ella Seham, he succeeded his elder brother Kwestantinos in AD 637 following the latter's untimely death in a hunting accident.
Ella Seham had enjoyed friendly relations with the early Islamic community, even twice sheltering large groups of Muslim refugees fleeing from Quraishi persecution. Kwestantinos had communicated with Muhammad after the Prophet had taken Mecca, and had encouraged missionaries to preach in Abyssinian cities. Wasan Sagad continued his father and brothers policy, but he is primarily remembered for leading the Abyssinian army to aid the Muslims in battle against Persia.
At the time of Wasan Sagad's accession, the Sassanid Persian empire along with large groups of Arab apostates had invaded Arabia and was now marching along the coast towards Mecca. Having suffered several defeats, and with his best general Khalid ibn al-Walid trapped in the north, Caliph Ali asked Abyssinia for assistance. An Abyssinian army landed in the Yemen that autumn, but suffered a terrible defeat at the Battle of Abyan. Wasan Sagad barely escaped with his life.
However, by the following year Wasan Sagad had managed to rebuild his army and returned to Arabia. By this time the Persians were besieging Mecca itself, and he found himself unable to reach the city in time before it fell. However, with his navy he did manage to sink the Persian supply fleet, and when a Roman army unexpectedly arrived in the area to offer assistance the Persians found themselves faced with no choice but to withdraw.
In the aftermath Wasan Sagad took the opportunity to speak face-to-face with Ali and others of Muhammad's companions. In May 638 he formally declared his belief in Islam and signed a new treaty of alliance with Ali and with the Emperor Heraclius.
In later years Wasan Sagad would expand the Abyssinian fleet and Abyssinia's influence overseas. Abyssinian merchant ships would trade all over the ocean, from Egypt to India to Madagascar, bringing the news of Islam everywhere they went. His successors would oversea the transformation of the country into a great power, transmitting urban civilization into the great unexplored interior of Africa and helping the continent to withstand its external enemies in the centuries to come.