Tripoli was a thriving trading post as early as the 8th century BC thanks to the constant comings and goings of traders from Tyre, Saida and Arwad (the latter in present-day Syria). Each community settled in its own area, a fact reflected in the city’s name, which derives from the Greek word tripolis, meaning ‘three cities’.

Conquered in turn by the Seleucids, Romans, Umayyads, Byzantines and Fatimids, the city was invaded by the Crusaders in AD 1102, who held on to it for 180 years and built its imposing – and still-standing – hilltop fortress, the Citadel of Raymond de Saint-Gilles. In 1289, the Mamluk Sultan Qalaun took control of the city and embarked upon an ambitious building program; many of the mosques, souqs, madrasas (schools for study of the Quran) and khans that remain in the Old City today date from either the Crusader period or subsequent Sultan Qalaun era. The Turkish Ottomans took over the city in 1516 and ruled in relative peace until 1920, when it became part of the French mandate of Greater Lebanon.

With a large influx of Palestinian refugees from 1948 onwards, the city became the site of ferocious fighting during the civil war. Huge UN-administered refugee camps still hug Tripoli’s outskirts, including the Nahr El Bared camp, now infamous for its protracted Palestinian/Lebanese army deadlock in 2007, during which nearly 400 Palestinians and Lebanese soldiers died. Until recently, factional clashes in Tripoli's suburbs were also a problem.