Sancho II was King of Portugal for more than two decades in the 13th Century. His relative indifference as a monarch led to civil war and his abdication.

He was born on Sept. 8, 1209, in Coimbra, the Portuguese capital. His father was Afonso II, and his mother was Urraca of Castile. When Sancho was born, however, his grandfather, Sancho I was on the throne.

Afonso II became king when his father died, in 1211. When Afonso died, 12 years later, he had created a large rift between the Portuguese crown and the Catholic Church. In fact, Pope Honorius III had excommunicated Afonso II, who had then promised to make amends but had not done so before he died. Sancho II, beginning his reign on March 26, 1223, signed a treaty with the pope and focused his military efforts on shoring up his country's possessions in the wake of the Reconquista, the ongoing struggle with Moorish forces in the Iberian Peninsula.

In 1240, Sancho married Mécia Lopes de Haro, a Castilian noblewoman. The couple had no children.

Sancho presided over a period of intense internal unrest and did little to pacify any of the warring elements. He eventually alienated enough of the population that they revolted, inviting the king's brother Afonso to become king instead. Civil war raged for two years, from 1245 to 1247. Afonso had been living in France, where had married Countess Matilda II of Boulogne, thereby coming Count of Boulogne. He marched at the head of an army into Portugal, however, and took up arms against his brother.

Afonso's forces eventually prevailed, and Sancho fled to Toledo, in Castile. He died there, on Jan. 4, 1248. On that day, his brother became officially King Afonso III.