One ruler of this name defeated his rival at the battles of Tarcal and Szina. A man of this name became king through the 1412 Compromise of Caspe and was known as the Infante of Antequera. A canonized Castilian king of this name was the father of Alfonso X and captured Cordoba in 1236.  Another ruler of this name gained portions of Hungary with the Treaty of Nagyvarad, but was unable to enforce it
One ruler of this name defeated his rival at the battles of Tarcal and Szina. A man of this name became king through the 1412 Compromise of Caspe and was known as the Infante of Antequera. A canonized Castilian king of this name was the father of Alfonso X and captured Cordoba in 1236.  Another ruler of this name gained portions of Hungary with the Treaty of Nagyvarad, but was unable to enforce it due to the election of John Zapolya's son to the Hungarian throne in 1540.  A Romanian monarch of this name reigned through World War I in between Carol I and Carol II, while a "benign" Holy Roman Emperor of this name abdicated in favor of Francis Joseph in 1848.  A king of this name re-married Germaine de Foix after his first wife died, and with that first wife sired Juana the Mad. FTP, give this name shared by a "Catholic" king who captured Granada and issued the Alhambra Decree expelling the Jews from Spain.
One ruler of this name defeated his rival at the battles of Tarcal and Szina.
Ferdinand [or Fernando]