Urraca's early life was shaped by the customs and expectations of her noble lineage. While she was not destined to inherit the Castilian throne due to the preference for male heirs, Urraca possessed unique power as a potential political alliance through marriage.

Urraca's first recorded mention is in the foundation charter of the Cistercian convent of Santa Maria de Las Huelgas in Burgos, issued in 1187. This convent would hold great significance for the royal family as a safe haven and burial site. Urraca's sister, Constanza, entered the convent as a child and eventually became a nun there, representing the family's dedication to the church. Urraca herself maintained a strong relationship with her family despite living in Portugal following her marriage.

In 1188, a treaty called the Treaty of Seligenstadt betrothed Urraca to the future King Alfonso IX of León. However, this marriage never materialized, and Alfonso IX went on to marry Teresa of Portugal, Urraca's sister's husband's sister. Urraca's marriage prospects remained significant due to the political alliances they could create, and she eventually married the King of Portugal, Afonso II, in 1205.

The marriage between Urraca and Afonso II was strategically advantageous for the Castilian dynasty as it extended their influence in the Iberian Peninsula. It also provided a period of relative peace between Castile and Portugal. Urraca's role as a representative of the Castilian dynasty in Portugal allowed her family to make decisions regarding her marriage and potential alliances.

During her marriage, Urraca faced challenges as her husband, Afonso II, was involved in a civil war with his sisters. Afonso's father, Sancho I, had made a testamentary bequest to his daughters, leaving them large estates and strategic castles. Afonso II, however, disputed the will and initiated a conflict with his sisters. This civil war emphasized the power and influence of royal women within Portugal at the time.

Urraca's marriage to Afonso II resulted in the birth of four children. However, her marriage was strained due to the political climate and her husband's ill health. Afonso II decided that Urraca should serve as regent to their son if he were to die before their son reached adulthood. Despite living in Portugal, Urraca maintained strong connections with her family in Castile. Her children were raised in different courts, including France and the court of Ferdinand III.

Urraca's life was intertwined with the monastery of Santa Maria de Las Huelgas, where her family had strong connections. Her sister, Constanza, played an active role in the monastery and became a representative of the institution to the outside world. The monastery symbolized the Castilian dynasty's dedication to both political alliances and the church.

Queen Urraca lived in a time of shifting alliances and political conflicts. Her marriage to Afonso II of Portugal served as a strategic alliance that extended the influence of the Castilian dynasty. Despite not ascending to the throne herself, Urraca played a vital role as a representative of her family and the potential for political alliances through marriage. Her life highlights the complex dynamics and significant roles that noble women played in medieval Iberian society.