Known as "bello e biondo", he was born illegitimate. His mother, Bianca Lancia, a Sicilian noblewoman, is said to have married his father, Emperor Friedrich II, on his deathbed. 
When about seventeen, Manfredo married B‚atrice de Savoie and by her fathered two children. In his early years he had been a great favourite of his father, sharing literature and other tastes. Before the Emperor died, he appointed Manfredo Viceroy of Southern Italy and Sicily. 
On the death of his half-brother, Konrad IV, Manfredo supported 

Konrad IV's son, Konradin. However, as the two-year-old Konradin was in Germany with his mother, Manfredo was crowned King of Sicily in 1258, taking up residence at Barletta. As he was a widower, in April 1259 he took for his second wife Helena Angela, a daughter of Michael 
I of Epirus, and by her fathered another three children. However, Pope Urban IV, continuing the feud against the Hohenstaufens, excommunicated Manfredo and handed the kingdom of 
Sicily to Charles of Anjou, a brother of the French King Louis IX. Charles of Anjou brought a well-equipped army to Beneventum where the two opponents met. As the battle turned against Manfredo and with his German barons defecting, he tried to inspire his men by going into the 
thick of the battle with great valour but was killed. The pope disallowed him a Christian burial and, as well, Charles of Anjou imprisoned Manfredo's widow, Helena, and her young children. Only 
Constance, Manfredo's surviving child by his first wife, escaped imprisonment. 

Source: Leo van de Pas