Maria died shortly after giving birth to Isabella II in 1212,[3] possibly by puerperal fever.

The betrothal was confirmed, but the Emperor still delayed his departure until August 1225, when he and Isabella were married by proxy in the City of Acre.

The contemporary chronicles described the exotic wedding celebrations, which took place in the Castle of Oria, and the indignant reaction of her father John of Brienne, now without royal authority.

[6] Aged 14, in November 1226, she gave birth to her first child, a daughter (referred to by some sources as Margaret); the baby died in August 1227.

On 25 April 1228 Isabella gave birth to her second child, a son, Conrad, in Andria, Bari, but a few days later, on 4 May, she died following childbirth complications.