The boy was called Joao, and as heir to the dukedom of Braganca, held the title Duke of Barcellos.
Recently, Simon Walker has highlighted the case of one John Kingsley, an esquire in the service of Henry IV's enemy, Thomas Mowbray, heir to the dukedom of Norfolk.
Henry I, still angst-ridden by my power, has ordered for my dukedom of Normandy to be invaded.
Thenceforward he remained faithful to his brother and, in 947, was given the dukedom of Bavaria.
His two sons died of the sweating sickness in 1551, when the dukedom became extinct.
With the support of the King of Naples, his brother raised an army and expelled him from the dukedom with his daughter.