He succeeded his father Thierry of Alsace.
Philip married Elizabeth of Vermandois, elder daughter of count Raoul III of Vermandois. The same year as his father died, his wife inherited a major portion of Vermandois. This pushed Flemish authority further south, and threated to completely alter the balance of power in northern France. But Elizabeth died without children in 1183, and soon after King Philip I of France seized Vermandois.
Philip had no children, and was succeeded in Flanders by his sister Margaret and her husband Baldwin V of Hainaut.
Thierry of Alsace
|Count of Flanders||
Margaret of Alsace