Philip was a younger son of Louis VI, Landgrave of Hesse-Darmstadt (1630–1678) and his second wife Princess Elisabeth Dorothea of Saxe-Gotha-Altenburg (1640–1709), daughter of Ernest I, Duke of Saxe-Gotha and Princess Elisabeth Sophie of Saxe-Altenburg.

[1] Philip fought for the Habsburgs in the Spanish War of Succession and became in 1708 Field Marshal and Supreme Commander of the Imperial troops in newly conquered Naples.

After the war in 1714, under influence of Prince Eugene of Savoy, he became governor of the former Duchy of Mantua until his death.

When he commanded the Austrian Army in Naples, he was patron of Nicola Porpora, and when he was governor of Mantua, he made Antonio Vivaldi Maestro di Cappella of his court.

[3] On 24 March 1693, in Brussels, Philip married Princess Marie Ernestine of Croÿ (1673–1714), daughter of Duke Ferdinand Joseph of Croy-Havré (1644-1694) and his wife, Countess Marie Joséphine Barbe van Halewijn de Hames (d.