Without any other sons to continue his line, the Margrave Azzo VII saw in Obizzo the only chance of survival of the House of Este and fought for his recognition as his heir. Obizzo was legitimated by the Pope Innocent IV in 1252, shortly after his mother was drowned in the Adriatic.
With no other male descendants to inherit his title, Azzo VII viewed Obizzo as the sole means of safeguarding the Este dynasty and contested for his rightful place as his successor. Obizzo was subsequently validated by Pope Innocent IV in 1252, shortly after his mother's demise in the Adriatic.