Afonso IV, also known as Afonso IV of Portugal, was the King of Portugal from 1325 until his death in 1357. He was the son of Afonso III and Beatrice of Castile. His reign was marked by conflicts with neighboring kingdoms and internal struggles, particularly with the nobility. Afonso IV is often remembered for his efforts to strengthen the monarchy and expand Portuguese territory. During his rule, Afonso IV faced challenges such as the Black Death, which significantly impacted the population and economy of Portugal. He is also known for his involvement in the Portuguese succession crisis, which led to the rise of his son, Peter I of Portugal, who succeeded him.