The Treaty of Trianon was signed between Hungary and most of the Allies of the First World War.
The Austro-Hungarian Empire had begun to collapse by the autumn of 1918, and the Hungarian Prime Minister declared the termination of the joint state on 31 October. Austria signed the Treaty of St. Germain on 10 September 1919 in which it recognised Hungary’s independence.
The Treaty of Trianon went on to strip Hungary of nearly three-quarters of its territory. Romania, Czechoslovakia, and Yugoslavia received the vast majority of this land and population. The border changes meant that over 3 million ethnic Hungarians found themselves living in a different country. Furthermore, the Treaty specified that one year after the date of signing these people would also lose their Hungarian nationality.
The territorial changes had a dramatic effect on Hungary’s economy. Large parts of the country’s former infrastructure and industry lay outside the new borders, while the loss of the coastline meant that it was both difficult and expensive to engage in international trade. Unemployment skyrocketed, while industrial output declined.
The treaty also placed severe limits on Hungary’s military which was forbidden from possessing an air force, tanks, and heavy artillery. The army was limited to 35,000 soldiers and conscription was banned, exacerbating the already mounting unemployment.
The social, economic and political effects of the treaty later led the historian and former British Ambassador to Hungary, Bryan Cartledge, to describe it as ‘the greatest catastrophe to have befallen Hungary since the Battle of Mohacs in 1526’.