falling into the hands of the enemy." To secure his southern frontier from Ottoman threats, Stephen wanted to liberate Wallachia – where the hostile Radu the Handsome, the halfbrother of Vlad Țepeș ruled – from Ottoman dominion. In 1470, he invaded the country and burned down the town of Brăila and in 1471, Stephen and Radu confronted each other in Moldavia, where the latter was defeated. Meanwhile, Genoa, which possessed several colonies in the Crimea, began to worry about Stephen's growing influence in the region; and ordered her colonies to do whatever was needed to revenge past mischief from which allegedly, the Genovese had suffered. The colonies in turn pursuaded the Tatars to attack Moldavia. Later that year, the Tatars invaded the country from the north, causing great damage to the land and enslaving many. Stephen replied by invading Tatar territory with Polish assistance. In 1472, Uzun Hassan of Ak Koyunlu invaded the Ottoman Empire from the east, causing a great crisis to the empire. He was defeated the following year, but this unexpected event, as it is explained in a contemporary source, encouraged Venice and Hungary to renew their war on the Ottomans, and Moldavia to free herself from any Ottoman influence. In 1473, Stephen stopped paying the annual tribute to the Porte and as a reaction to this, an Italian letter, dated from 1473 to Bartolomeo Scala, secretary of the Republic of Florence, reveals that Mehmed had left Constantinople on 13 April and was planning to invade Moldavia from land and sea. Stephen still hoped to make peace with Radu and asked the Polish king to work as mediator. The peace attempts failed and the conflict intensified with three leaders challenging each other for the Wallachian throne: Radu, who was supported by Mehmed; the seemingly loyal Basarab Laiotă, who at first was supported by Stephen; and Basarab Ţepeluş cel Tânăr—who would gain the support of Stephen after Laiotă's betrayal. A series of "absurd" clashes followed, starting with another confrontation between Stephen and Radu on 18–20 November, at Râmnicu Sărat, where the latter suffered his second defeat at the hands of the Moldavian "warlike" prince. A few days later, on 28 November, the Ottomans intervened with an army consisting of 12,000 Ottomans and 6,000 Wallachians, but "they incurred heavy losses and fled across the Danube." After capturing the castle of Bucharest, Stephen put Laiotă on the throne, but on