Isaac II Angelos
Constantine's third son Andronikos Doukas Angelos, was the progenitor of the imperial Angelos dynasty. In 1185, Andronikos' son Isaac II Angelos deposed Andronikos I Komnenos and was proclaimed Byzantine Emperor. Irene Angelina, a daughter of Isaac II Angelos, married Philip of Swabia, King of the Germans. Their daughters married into a number of western European royal and princely families. Many of the extant aristocratic families of Europe are, therefore, descendants of the Angeloi. Isaac was deposed by his brother Alexios III Angelos, who was in turn overthrown by Alexios IV Angelos with the aid of the Fourth Crusade. Under the corrupt and dissolute reign of the Angelos dynasty, the Byzantine empire deteriorated and soon fell prey to Latin crusaders and Venetians in the Fourth Crusade.