Afonso II was King of Portugal for a dozen years in the 13th Century. He presided over an initial expansion of his country's international reputation.

He was born on April 23, 1185, in Coimbra, the Portuguese capital. His father was Sancho I, at the time the second-in-command to his father, King Afonso I. Sancho took the throne eight months later, when his father died. Punctuating Sancho's reign were struggles against Galicia and León in the north and the Moors in the south. The land was relatively stable when he died, in 1211.

By that time, Afonso had married. In 1206, he had wed Urraca of Castile, whose father was Alfonso VIII of Castile. The couple had four children, all of whom lived into adulthood: Sancho (1207), Afonso (1210), Eleanor (1211), and Ferdinand (1218).

Afonso took the throne on March 26, 1211. It was during his reign that Portugal had its first body of written laws, courtesy of the first definitive meeting of the parliament-like Cortes, and its first set of ambassadors, sent by Afonso to establish relations with other European kingdoms.

During this time, both Portugal and Spain were engaged, off and on, in the Reconquista, the taking back of territory on the Iberian Peninsula that had been conquered by Moorish armies. Portuguese forces took part in one of the most significant of these conflicts, defeating Almohad forces at the Battle of Las Navas de Tolosa in 1212. A confident Afonso was then able to take possession of Alcacer do Sal a few years later.

He suffered from obesity, caused in part by an illness suffered when he was young. He was known as Afonso the Fat.

Afonso I had given much power and privileges to the Catholic Church. The second King Afonso took away some of those entitlements; the result was a great conflict between church and state, punctuated by Afonso's being excommunicated by Pope Honorius III.

Afonso II died on March 25, 1223. Succeeding him as King of Portugal was his oldest son, who became Sancho II.