OTL, la Gran Contessa, Matilda of Canossa, died without heir in 1115.
She controlled a very large domain in northern Italy within the Holy Roman Empire, but in the aftermath of her death, the Emperor did not name a succesor to her many estates and allowed the leading members in each of her cities to chose a leader from amongst their own, heralding the age of the Italian city-states.
WI she had had an heir to inherit her many lands and keep them together? Could we perhaps see an earlier breakup of Italy from the HRE, or an independent and united Italy centuries earlier?