Leo Phokas the Elder

As Domestic of the Schools, the Byzantine army's commander-in-chief, he led a large-scale campaign against the Bulgarians in 917, but was heavily defeated at the battles of Acheloos and Katasyrtai.

Left unsupported by both the Pechenegs and the fleet, Phokas suffered a crushing defeat at the hands of Tsar Symeon at the Battle of Acheloos.

With this stroke, Zoe lost all control of the situation, and at Theodore's urging, the young Emperor appointed the Patriarch Nicholas Mystikos as regent.

[6][7][8] Leo apparently believed that Lekapenos, in view of his lowly origins, could never possibly put forward a credible claim for the imperial throne.

Events proved that he had severely miscalculated: on March 25, 919, Lekapenos managed to gain entrance to the imperial palace, occupied it and secured his appointment as magistros and commander of the Hetaireia.

A few weeks later, he married his daughter Helena to the young Emperor and assumed the title of basileopator, becoming the virtual ruler of the Byzantine Empire.

The Byzantine rout at Acheloos, from the Madrid Skylitzes .
Gold solidus of Emperor Constantine VII (r. 913–959) with Romanos Lekapenos. After overcoming the rebellion of Leo Phokas, Lekapenos promoted himself to Caesar and was eventually crowned as senior emperor ( basileus autokrator ) in December 920, ruling until his abdication in December 944.
The capture and blinding of Leo Phokas.