There is no one, official, united Hungarian Orthodox Church. Many Orthodox churches are present in the country or lay claim to some territory of the former Austro-Hungarian Empire, but most Byzantine or Eastern Christians of the modern, sovereign nation of Hungary belong to the Byzantine Catholics, united with the Pope of the Roman Catholic Church. Over 50% of the population of Hungary is Roman Catholic. Another 20% is Calvinist. The largest minority faith group is the Lutherans. Greek or Byzantine Catholics and Eastern Orthodox do not make up a significant percentage of the demographic.