Alfonso IV was a king of Portugal who reigned from 1325 to 1357. He was the son of Afonso III and Beatrice of Castile. His reign is noted for efforts to strengthen the kingdom and improve its economy, as well as for his involvement in the Iberian Peninsula politics of the time. During his rule, Alfonso IV faced challenges, including conflicts with neighboring kingdoms and internal disputes. He is also known for his support of the Portuguese nobility and for fostering trade, which helped to enhance Portugal's position in Europe. His legacy includes a focus on stability and growth for the nation.