Chittagong, the second largest city and main port of Bangladesh, was home to a thriving trading post of the Portuguese Empire in the East in the 16th and 17th centuries.

In 1528, the Sultan of Bengal permitted the Portuguese to establish factories and customs houses in the Port of Chittagong.

[10] The cartaz system was introduced and required all ships in the area to purchase naval trading licenses from the Portuguese.

[11][12] In 1590, the Portuguese conquered the nearby islands of Sandwip under the leadership of António de Sousa Godinho.

[15] The harbour of Chittagong became the most important port to the Portuguese because of its location, navigational facilities and safe anchorage.

[18][10] The increased commercial presence included bureaucrats, merchants, missionaries, soldiers, adventurers, sailors and pirates.

[7] Major traded products included fine silk, cotton muslin textiles, bullion, spices, rice, timber, salt and gunpowder.

The fall of the Bengal Sultanate and the rise of the Arakanese Kingdom of Mrauk U changed the geopolitical landscape.

[23] In 1629 the Portuguese under the command of Diego Da Sa raided Dhaka and took many prisoners including a Syed woman, the wife of a Mughal military officer and carried her off in chains to Dianga.

[25][26] In 1666, the Mughal viceroy Shaista Khan retook control of Chittagong after defeating the Arakanese in a naval war.

[27] The Mughal conquest of Chittagong brought an end to the Portuguese dominance of more than 130 years in the port city.

[28] The conquest of the port of Chittagong was similarly aimed mainly at driving Arakanese slave raiders out of Bengal.

[26] The Mughals attacked the Arakanese from the jungle with a 6500-man army supported by 288 ships of war bound for the seizure of Chittagong harbour.

[18] From Chittagong, the Portuguese proceeded to establish settlements in other Bengali ports and cities, notably Satgaon, Bandel and Dhaka.

[33] The oldest churches in Bangladesh and West Bengal trace their origins to Portuguese missionary missions which arrived in Chittagong in the 16th century.

[33] After the independence of Bangladesh, Portugal recognised it on 20 December 1974 following the Carnation Revolution, when it established relations with many decolonised nations.

Darul Adalat, the first court building of Chittagong is located in the Government Hazi Mohammad Mohshin College campus, is a structure built by the Portuguese.

Some geographical place names remain, like Dom Manik Islands, Point Palmyras on the Orissa coast, Firingi Bazar in Dhaka and Chittagong.