Late in the second decade of Maleinos II's reign, his leading general, Grand Domestikos Stylianos declared himself Avtokrator and led troops loyal to him from the frontier with the Khamorth to march on Videssos the city. Maleinos drew troops from the provinces including as far north-east as Skopentzana. His forces succeeded in defeating Stylianos near Develtos at mid-summer forcing the latter to flee back to the frontier.
Stylianos regrouped drawing more soldiers from the frontier forts leaving Videssos vulnerable to marauding Khamorth. Meanwhile Maleinos drew soldiers from the Empire's borders leaving the empire vulnerable to attack by the Halogai and the Khamorth. Each thought that after they had defeated the other, they could regain lost lands and each was mistaken.
The two met on the battlefield again in early autumn near Imbros. This time, Stylianos was victorious. He attempted to block Maleinos' retreat back to the City but despite the running fight, Maleinos succeeded in escaping. Maleinos retained enough troops to not be besieged within the city but his area of authority was greatly diminished.
Stylianos soon threatened Videssos the city itself. Rather then being besieged by the usurper, Maleinos charged outside the city's walls and offered his former general battle. Stylianos being the greater military tactician soon destroyed Maleinos' army and Maleinos himself died on the battlefield.
Stylianos marched into Videssos the city and crowned himself Avtokrator.