At the age of eight his first marriage was contracted with Blanche of Castile but she proved mentally retarded and so the marriage was annulled. His second marriage was contracted when he was sixteen but he had to wait four years before Constance came to Portugal. Constance brought with her a beautiful Castilian girl, Ines de Castro, and Pedro fell madly in love with her. Nevertheless Pedro and Constance still produced two sons. Luiz, the first born, had Ines de Castro as godmother which, according to the church, placed her in a prohibitive affinity with Pedro which should bar any subsequent marriage. 

In 1345 when Constance died after giving birth to her second son, Pedro and Ines began living openly together and they became the parents of four children. Although Pedro's father urged him many times 
to remarry, Pedro claimed that his grief for Constance prevented him from making any other marriage. At the same time Ines not only proclaimed that she was not Pedro's wife, but 'she never was, nor 
could be, his wife'. 

Ines had two brothers who persuaded Pedro to claim the Castilian throne; this alarmed Pedro's father, who feared Pedro might set aside Constance's children in favour of those by Ines de Castro. Alfonso IV went to Coimbra to kill Ines de Castro himself while Pedro was absent, but was dissuaded by the pleas of her little children. However, three courtiers returned after Alfonso IV had left and killed Ines de 
Castro. 

Pedro, who had been in the north of Portugal, then raised an army and attacked his father. However, the short and bloody civil war was ended by Queen Beatrice who, mediating between her husband and son, restored peace in Portugal. Two years later, in May 1357, Alfonso IV died and Pedro I was king of Portugal. 

He was now in a position to avenge Ines, which he did by having Castile hand him two of her murderers whom he had executed before his eyes, while the third murderer escaped to England. Pedro I now declared that he had indeed married Ines de Castro on 1 January 1354, a year before her murder. He then had her body exhumed from her grave in Coimbra and taken to Alcobaca where, dressed in royal robes and placed on a throne, was solemnly crowned on 24 April 1361 in the presence of the whole court and then reinterred. As king he preferred to be present whenever justice was to be done, sometimes in disguise, to expose corrupt or unfair judges. 

Otherwise he went hunting, feasting and womanising. The result of the latter was an illegitimate son who later on became king of Portugal in due course. Pedro I was only forty-six when he died. 
 

Source: Leo van de Pas