 Having secured the Duero, Ferdinand began to bring the valley of the Mondego under his control, first taking Viseu in its middle stretch on 25 July 1058 and then moving down towards the sea.It was "a long and grueling battle" before Coimbra, at the mouth of the Mondego, was taken on 25 July 1064 after a six-month siege.In 1065, Ferdinand embarked on his last military campaign.