After Bermudo III’s death in battle, his sister Sancha inherited the throne. Since she was married to Fernando, count of Castille, her husband automatically became king of León. However, since his men had murdered the previous king, he was not well received by the Leonese people, and wasn’t allowed to reenter the capital or be crowned until a year later. The documents about this period of time will always add Sancha’s name next to Fernando’s since she was the legitimate queen and he was just a King consort. Since the idea of a king consort didn’t exist in the Middle Ages, Fernando fully acted like a king.
Even so, chronicles say that it took him sixteen years to stabilize the unhappiness towards him.
Although Fernando’s brother, García Sánchez III, king of Pamplona, had helped him face Bermudo III, both brothers declared war against each other some time after that. The Navarran was defeated and killed in the battle of Atapuerca (1051).
Sancha and Fernando confirmed Alfonso V’s Charter of León, and in 1055 they summoned a Church Council in Coyanza (Valencia de Don Juan), in which they agreed on religious reforms.
Between 1057 and 1064 the King and Queen recovered the cities that Almanzor had occupied in the north of Portugal, such as Lamego, Viseo and Coimbra. In addition, they imposed themselves with ease on the main “taifa” kingdoms of al-Ándalus and charged “parias”, which were tributes in the form of gold paid annually.
Sancha and Fernando donated a thousand gold dinars annually to the French Monastery of Cluny. These riches contributed to the development of the architectural program of the Abbey that would spread Romantic art throughout Europe.
In 1063, they also facilitated the movement of supposed remains of San Isidoro de Sevilla to the San Pelayo monastery in León, which would be expanded and renovated, and would have its name changed to hold the name of Santo Visigodo Sevillano.
On that same year, Sancha and Fernando agreed on splitting up the kingdom between their three sons: Sancho, the firstborn, would receive Castille, that now held the title of kingdom; Alfonso, the favorite son, would receive León, containing the capital and biggest territory; and the youngest, García, would receive Galicia, including the north of current Portugal.
Fernando I passed away in 1065, and the division of the kingdom among the three sons took effect. The Queen Sancha, throughout the rest of her life, supervised her sons.