Complex sentence: Bianca Lancia d'Agliano (also called Beatrice and Blanche) was an Italian noblewoman, who was the mistress and later wife of emperor Frederick II of Hohenstaufen, although the marriage, conducted while she was on her deathbed, was considered non-canonical.
Split into simpler sentences: Bianca Lancia d'Agliano (also called Beatrice and Blanche), an Italian noblewoman, was the mistress and later the wife of emperor Frederick II of Hohenstaufen. The marriage was conducted while she was on her deathbed, therefore it was considered non-canonical.