The Sinhalese arrived in the island in the 6th century BC, probably from northern India. Buddhism was introduced a few centuries later, and became the main religion. Tamils, also from India, established themselves on the northern and eastern parts of the island. Some were brought by the British, as indentured labour. Ceylon became part of the British empire in 1815. It gained independence in 1948, and changed its name to Sri Lanka in 1972. The Sinhalese constitute 74 percent of the population, the Tamils 10 percent. Since 1983, the country has suffered a violent civil war between the Tamil Liberation movement and the government. A cease-fire was signed in 2001, with the help of Norway. In 2005, negotiations for a political solution were still going on. Sri Lanka's economy is based on agriculture, processing and manufacturing industries, and tourism, which has been affected by the on-going conflict. The majority of the population is poor and depends on subsistence farming. The island was hit hard by the tsunami of December 2004. The Catholic Church is the oldest and largest church. Methodism and Anglicanism came in the 19th century. There is a large Assemblies of God church (Pentecostal). The National Christian Council is the ecumenical body, and the Evangelical Alliance of Sri Lanka is affiliated with the WEA. Christians are a minority in Sri Lanka. Some groups have created tensions because of their aggressive methods of evangelism. The Catholic Church, the National Christian Council, and the Evangelical Alliance have cooperated in trying to maintain peaceful relations with the Buddhists and others.