Under Stephen the Great, who took the throne and subsequently came to an agreement with Casimir IV of Poland in 1457, the state reached its most glorious period. Stephen blocked Hungarian interventions in the Battle of Baia, invaded Wallachia in 1471, and dealt with Ottoman reprisals in a major victory (the 1475 Battle of Vaslui); after feeling threatened by Polish ambitions, he also attacked Galicia and resisted Polish reprisals in the Battle of the Cosmin Forest (1497). However, he had to surrender Chilia (Kiliya) and Cetatea Albă (Bilhorod-Dnistrovskyi), the two main fortresses in the Budjak, to the Ottomans in 1484, and in 1498 he had to accept Ottoman suzerainty, when he was forced to agree to continue paying tribute to Sultan Bayezid II. Following the taking of Hotin (Khotyn) and Pokuttya, Stephen's rule also brought a brief extension of Moldavian rule into Transylvania: Cetatea de Baltă and Ciceu became his fiefs in 1489.