Tripoli (trĭpˈəlē) [key] or Tarabulus täräbˈŏlŏs, ancient Tripolis, city (1996 est. pop. 300,000), NW Lebanon, on the Mediterranean Sea. Citrus fruits, cotton, and other goods are exported from Tripoli. It has an oil refinery and is the terminus of an oil pipeline from Iraq. It was probably founded after 700 B.C., as there is no mention of it until Persian times when it was the capital of the Phoenician federation of Tyre, Sidon, and Aradus and was divided into three sections. The city flourished under the Seleucid and Roman empires. In A.D. 638 it was captured by the Arabs. After a long siege it was taken (1109) by the Crusaders; during the siege its great library was destroyed. Tripoli was sacked by the sultan of Egypt in 1289 and was later rebuilt. The British conquered it from the Turks in 1918, and it became part of Lebanon in 1920. The old part of the city, around the harbor, contains the remains of fortified towers and walls. The city's population is comprised largely of Sunni Muslims. Tripoli was the scene of heavy fighting during the 1975–76 civil war. It became the headquarters for the Palestine Liberation Organization (PLO) after the Israeli invasion of Lebanon in 1982. In the wake of rebellion against the PLO in 1983, large numbers of Palestinian rebels fled the city. Syrian military forces began to move into the city in the mid-1980s; like Beirut, it became a Lebanese city marked by battles for hegemony.