John, Duke of Slavonia

John, Duke of Slavonia (1354-1360) was a Hungarian prince of the Capetian House of Anjou.

John was born in 1354. His parents were Stephen, Duke of Slavonia, son of King Charles I Robert of Hungary, and Margaret of Bavaria, daughter of Holy Roman Emperor Louis IV. Stephen died the same year and John succeeded him as Duke of Slavonia, with his mother Margaret as regent. John did not only assume the Duchy of Slavonia on his father's death; the newborn also became heir presumptive to the throne of his paternal uncle, King Louis I of Hungary.

King Louis I requested that his maternal uncle, King Casimir III of Poland, adopt John as his heir presumptive, which he did in 1355. Duchess Margaret remarried in 1356, but kept the regency over the duchy. However, a war broke out between the Kingdom of Hungary and the Republic of Venice in the spring of the same year and the royal court decided to end Slavonia's autonomy.

John died in 1360. He was survived by both his uncle Louis and his granduncle Casimir, and consequently never ascended either throne. His older sister Elizabeth replaced him as heir presumptive to the Hungarian throne.

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