Battle of Baia
Main article: Battle of Baia
The Battle of Baia was fought on Dec.15, 1467 against the armies of Hungarian King, Matthias Corvinus. The battle was the last Hungarian attempt to subdue the independent Moldavia, as previous attempts had ended in failure. Corvinus invaded Moldavia due to Stephen's annexation of Chilia — a fortress and harbour at the coast of the Black Sea, which at the time was controlled by Hungarian and Wallachian forces, though it had belonged to Moldavia centuries earlier.
The conflict ended with a bitter defeat for the Hungarians, who had an army more than three times the size of the Moldavian force. This put an end to all Hungarian claims on Moldavia. Corvinus almost died after being thrice wounded by arrows and barely made his escape to Transylvania.
In 1468, Stephen campaigned in Transylvania, found Aron and had him executed.Stephen and Corvinus would later negotiate a peace treaty and become allies; in 1475, Corvinus sent 1,800 soldiers that assisted Stephen in his victory at the Battle of Vaslui.
Battle of Vaslui
Main article: Battle of Vaslui
Coat of arms of Moldavia in 1481, at Putna Monastery.
The Battle of Vaslui (Battle of Podul Înalt or the Battle of Racova) was fought on Jan.10, 1475, against the Ottoman Beylerbeyi of Rumelia, Hadım Suleyman Pasha. The battle took place at Podul Înalt (the High Bridge), near the town of Vaslui, in Moldavia (now part of eastern Romania). The Ottoman troops numbered up to 120,000, facing about 40,000 Moldavian troops, plus smaller numbers of allied and mercenary troops.
Stephen inflicted on the Ottomans a decisive defeat that has been described as "the greatest ever secured by the Cross against Islam," with casualties, according to Venetian and Polish records, reaching beyond 40,000 on the Ottoman side. Mara Brankovic (Mara Hatun), who had formerly been the younger wife of Murad II, told a Venetian envoy that the invasion had been worst ever defeat for the Ottomans.Stephen was later awarded the title "Athleta Christi" by Pope Sixtus IV, who referred to him as "Verus christiane fidei aletha" (The true defender of the Christian faith).
According to the Polish chronicler Jan Długosz, Stephen did not celebrate his victory; instead, he fasted for forty days on bread and water and forbade anyone to attribute the victory to him, insisting that credit be given only to "The Lord".
After the disaster of the Battle of Vaslui, the Sultan Mehmed II assembled a large army and entered Moldavia in June 1476. Meanwhile groups of Tartars from the Crimean Khanate (the Ottomans' recent ally) were sent to attack Moldavia. Romanian sources may state that they were repelled,.Other sources state that joint Ottoman and Crimean Tartar forces "occupied Bessarabia and took Akkerman, gaining control of southern mouth of Danube. Stephan tried to avoid open battle with the Ottomans by following a scorched-earth policy." In the process the Moldavians forces ended up being dispersed throughout the country, leaving only a small force of about 12–20,000 men, led by Ștefan cel Mare himself, to face the main Ottoman attack.
The battle began with the Moldavians luring the main Ottoman forces into a forest that was set on fire, causing some casualties to the attacking Ottoman army in the forest. According to another battle description, the defending Moldavian forces repelled several Ottoman attacks with steady fire from hand-guns.The attacking Turkish Janissaries were forced to crouch on their stomachs instead of charging headlong into the defenders positions. Seeing the imminent defeat of his forces, Mehmed charged with his personal guard against the Moldavians, managing to rally the Janissaries, and turning the tide of the battle. Turkish Janissaries penetrated inside the forest and engaged the defenders in man-to-man fighting.
The Moldavian army was utterly defeated (casualties were very high on both sides), and the chronicles say that the entire battlefield was covered with the bones of the dead, a probable source for the toponym (Valea Albă is Romanian and Akdere Turkish for "The White Valley").
Ștefan cel Mare retreated into the north-western part of Moldavia or even into the Polish Kingdom and began forming another army. The Ottomans were unable to conquer any of the major Moldavian strongholds (Suceava, Neamț, Hotin)and were constantly harassed by small scale Moldavians attacks. Soon they were also confronted with starvation, a situation made worse by an outbreak of the plague, and were driven out of the country, many of then dying while crossing the Danube river. The Sultan returned to Istanbul without considering himself defeated, but also without conquering anything.
Romanian Orthodox Church decided to canonize Stephen. The canonization was enacted on June 20, 1992 by the Synodic Council of the Romanian Orthodox Church. Stephen is called "Saint Voivode Stephen the Great". His feast day in the Romanian Orthodox calendar is July 2, the day of his death.