The Polish are a Slavonic people. Poland as a nation emerged in the 10th century and reached its golden age in the 16th century when it formed a union with neighbouring Lithuania which extended into Ukraine. At the end of the 18th century Poland was partitioned between Russia, Prussia, and the Austro-Hungarian Empire. It regained part of its territory as a republic after World War I, but was invaded by Nazi Germany in 1939 and divided between Germany and the Soviet Union. Poland lost six million people in World War II, half of them Jews, and the country was completely destroyed. It became part of the Soviet bloc after the war. Poland was a stronghold of anti-Communist resistance. From 1980 onwards, the independent trade union Solidarnosc spear-headed reform and its leader, Lech Walesa, became the first president of democratic Poland in 1990. The country has undertaken to restructure its economy, based on agriculture and industry, and joined the European Union in 2004. One of its major problems through 2005 remains high unemployment. Poland is a Catholic country. Its society, culture, and public life are deeply marked by the influence of the majority Catholic Church. But the minority Orthodox and Lutheran churches are also part of Poland's history, as are the Old-Catholic churches. Together with the smaller Methodist, Reformed and Baptist churches they form the Ecumenical Council of Poland. The Assemblies of God (Pentecostal) are present, as well as some Evangelical churches. The Polish Evangelical Alliance is affiliated with the WEA.