In 1043 a peace treaty between Henry III and King Samuel Aba of Hungary fixed the western border of the Kingdom of Hungary along the Leitha and Lafnitz rivers, among others. The territory of the present-day Burgenland became the western border-zone of the medieval Kingdom of Hungary until the 16th century. The majority of the population was Germanic. There was also immigration in the Middle Ages from the neighbouring Austria. During occupation of Hungary by the Ottoman Empire some parts of today's Burgenland stayed within Habsburg rule. After the Austro-Hungarian empire was formed in 1867 Burgenland was part of the Hungarian part of the monarchy. Because 74% of the inhabitants were of German origin the area came to the new formed Republic of Austria. In the time till the Second World War many people emigrated to the United States. It is said that Chicago is the largest town of the Burgenland.