He was a member of the Catholic Koháry line of the Saxe-Coburg and Gotha-Koháry and an elder brother of Ferdinand, tsar of Bulgaria.

[1] On the morning of 30 January 1889, he and Count Josef Hoyos-Sprinzenstein and valet Johann Loschek discovered the bodies of Rudolf and his teenage mistress Baroness Mary Vetsera, who had also been shot dead.

In Brussels on 4 February/4 May 1875, Philipp married Louise, princess of Belgium, both his second cousin and first cousin once removed, daughter of Leopold II, king of the Belgians and granddaughter of Leopold I, king of the Belgians, brother of Philipp's grandfather Ferdinand, and Louise of Orléans, sister of Phillip's mother Clémentine.

[3] The reason for the separation was her long-standing relationship with Count Géza of Mattachich-Keglevich (1867-1923), with whom Philipp had dueled on the orders of Emperor Franz Josef I.

Several commemorative medals were issued during his lifetime, for example in 1875 on the occasion of his marriage to Louise and in the same year for his honorary membership of the Belgian Numismatic Society.