Thanlyin became a prominent port city in during the
Hanthawaddy kingdom when the port of
Bago became silted in the 15th century. In 1599, the city was conquered by the
Kingdom of Mrauk U's Portuguese mercenaries. The leader of the mercenaries
Filipe de Brito e Nicote was made governor of the city. However, in 1603, De Brito declared independence, and after defeating the invading Arakanese navy in 1604 and 1605, successfully established
Portuguese rule over Syriam (or Sirião in Portuguese) under the Portuguese
viceroy of Goa. Ten years later,
Anaukpetlun of the
restored Taungoo dynasty retook the city, and executed de Brito by
impalement. Thanlyin remained the major port of the Taungoo kingdom until the mid-18th century. In the 1740s, Thanlyin was made the base of the
French East India Company for their help in the Mon's
reestablishment of Hanthawaddy Kingdom. The arrangement lasted until 1756 when King
Alaungpaya of
Konbaung dynasty captured the city. From then on, the importance has shifted to
Yangon across the river, which Alaungpaya founded just a year earlier. Thanlyin became part of the
British Empire in 1852 after the
Second Anglo-Burmese War. The British made the city into the oil refinery center of the country in the early 20th century to process the oil shipped from central Burma. The refinery was destroyed during
World War II. The Thanlyin refinery was rebuilt in 1957, and underwent expansion in 1979 with Japanese assistance. In 1979 a pipeline was completed between Syriam and the Mann oilfield. Since the 1990s, the city has undergone major changes. Thanlyin was finally connected to Yangon by road in 1993 when the
Thanlyin Bridge was built. In the late 1990s, Thilawa Port was built to handle the container ships away from Yangon's ports. The city's population has increased from 43,000 in 1983 to 123,000 in 1996. As of 2023, the town had a population of 78,667 people. ==Transport==