Northern Transylvania Transylvania, and in 1920 the Treaty of Trianon assigned Transylvania to the Kingdom of Romania. In June 1940, after Romania was forced (as a consequence of Molotov–Ribbentrop Pact) to settle a claim to the Soviet Union over Bessarabian and Bukovinian territories, Hungary attempted to regain Transylvania, which it had lost in World War I. Germany and Italy pressured both Hungary and Romania to resolve the situation in a bilateral agreement. The two delegation met in Turnu Severin but the negotiations failed due to a demand for a 60,000 square kilometers territory on Hungarian side and only a population exchange on
Transylvania 1526, Transylvania was a voivodeship in the Kingdom of Hungary, led by a voivode appointed by the King of Hungary. After the Battle of Mohács in 1526, Transylvania became part of the Kingdom of János Szapolyai. Later, in 1570, the kingdom transformed into the Principality of Transylvania, which was ruled primarily by Calvinist Hungarian princes. During that time, the ethnic composition of Transylvania transformed from an estimated near equal number of the ethnic groups to a Romanian majority. Vasile Lupu estimates their number already more than one-third of the population of Transylvania in a letter to the sultan around 1650.