Originally, as a younger son, he was destined for the church but in 1193, when he was only seventeen, he preferred the political life and in 1195 his brother, Emperor Heinrich VI, made him Duke of Tuscany then Duke of Schwaben (Suabia) in 1196. In 1197 he married Irene (Maria) Angela, daughter of the Byzantine Emperor. 
When his brother Emperor Heinrich VI died in September 1197, Philipp was excommunicated by the church. This added to his troubles by having Heinrich VI's young son acknowledged as King of the Romans (Emperor Elect). Because this nephew, Friedrich II, was only a boy and absent in Sicily, Philipp was persuaded that he himself should accept the kingship. On 8 March 1198 at M?hlhausen, the German princes did elect him as King of the Romans and, on 8 September 1198 at Mainz, he was crowned by the Archbishop of Tarantaise. 
However, the opponents of the Hohenstaufen denied the validity of his election and provided their own candidate, Otto of Brunswick. Even though supported by the majority of princes and the French king, he was unable to defeat Otto IV of Brunswick. To put and end to the fighting, the intervention of the reluctant Pope Innocent III was requested. As Philipp was still excommunicated and, as well, the Hohenstaufen had previously threatened the papacy, Pope Innocent III decided in favour of Otto IV of Brunswick on 11 March 1201. At the same time he also placed Philipp's followers under the Church's ban. 
Philipp lost a few supporters but also gained others who had previously opposed him. Of these, the most important, Archbishop Adolf of Cologne, recrowned Philipp as King of the Romans in Aachen on 6 January 1205. Gradually Philipp's position improved and, on 27 July 1206, he defeated Otto IV at Wassenberg near Cologne, driving him away from the Rhineland. At the same time, Philipp approached Pope Innocent III and the concessions offered, as well as the collapse of Otto IV's 
cause, had the church's ban lifted on 1 November 1207. Part of the agreement with the pope included the marriage of one of Philipp's daughters to a nephew of the pope. However, before the settlement could be finalised, Otto von Wittelsbach, who had been promised in marriage to the same daughter, in his fury murdered Philipp on 21 June 1208 at Bamberg.
 

Source: Leo van de Pas