To improve relationships with the Byzantine Empire, in April 1195 Henry VI betrothed Philip to Irene Angelina, a daughter of Emperor Isaac II and the widow of junior King Roger III of Sicily, a lady who was described by Walther von der Vogelweide as "the rose without a thorn, the dove without guile": she was among those taken prisoner by the Emperor when he invaded Sicily in 1194. In early 1195, Philip accompanied his imperial brother on his journey to Sicily and at Easter 1195 he was made Margrave of Tuscany, receiving the disputed Matildine lands; in his retinue in Italy was the Minnesinger Bernger von Horheim. Philip's rule in Tuscany there earned him the enmity of Pope Celestine III, who excommunicated him. On 3 May 1196, Philip was documented for the last time as Margrave of Tuscany. After the murder of his brother Conrad in August 1196, Philip succeeded him as Duke of Swabia. The marriage of Philip and Irene Angelina (renamed Maria upon her wedding) probably took place at Pentecost (25 May) 1197 in the Gunzenle hill near Augsburg. Five daughters were certainly born from the union: