When Urraca I passed away in 1126, her son Alfonso was immediately crowned in the city of León. He had to face rebellions led by unsatisfied nobles, and also confront his stepfather Alfonso I de Aragón, who continued to occupy part of Castille.
In 1128 Alfonso VII married Berenguela, the daughter of the count of Barcelona, which led to the arrival of a good number of Catalans to the Leonese Court. It was around this time that Afonso Henriques imposed himself on his mother Teresa as count of Portugal, and started acting like the king of that territory.
Nevertheless Alfonso VII continued to strengthen his power, not only inside his kingdom, but also all around the Peninsula. Alfonso I de Aragón passed away in 1134 after a disastrous defeat against the muslims, and Alfonso VII came to help Zaragoza. It is believed that this was the moment when the city adopted the lion as a symbol, in appreciation to the Leonese king: in any case, it is a fact that Alfonso VII was the first to wear this heraldic emblem.
All of the monarchs and Christian lords of the Peninsula recognized the superiority of the King of León by watching his imperial coronation in León in May of 1135. Afonso Henriques of Portugal was the exception, and finally Alfonso VII recognized the title of king for him in 1143. After this coronation Afonso became Afonso I of Portugal, and his region officially became a new kingdom.
After numerous triumphs in his campaigns against al-Ándalus, Alfonso VII suffered an invasion by the Almohads, a new fundamentalist Muslim empire from the north of Africa, and ended up losing a few of his conquests.
Years before passing away he left a division of his goods set up for his two sons: Sancho would lead the crown of Castille, and Fernando the crown of León.
Alfonso passed away in Puerto del Muradal (Ciudad Real), on August 21st of 1157. He was buried near Toledo.