Alexander III (870 - 913) was the son of Basil I and the brother of Byzantine emperor Leo VI.
Alexander had been named co-emperor during Leo's rule. Upon Leo's death in 912 Alexander became full emperor, and regent for Leo's son Constantine. His reign was very brief. As emperor, he re-instated Patriarch Nicholas Mysticus to the throne of Saint Andrew and defrocked Euthymius who had replaced him.
While the Bulgars were preparing for war against the Empire in 913, Alexander died. On his deathbed he named Constantine his heir (the boy became Constantine VII).
A portion of content for this article is credited to Wikipedia. Content under GNU Free Documentation License(GFDL)