The port is located on Antsiranana Bay, which is one of the largest deepwater harbors in the Indian Ocean. However, its remote location and, until recently, the bad road to the south caused it to become unimportant for freight shipping traffic. Communication with other sites of Madagascar is provided by Arrachart Airport.
Originally the bay and city used the name “Diego Suarez”, after Portuguese navigator Diogo Soares, who visited the bay in 1543. During the 1880s, the Diego Suarez bay was coveted by France. The country desired it as a coaling station for its steamships. Following the first Franco-Hova War, a treaty was signed by Queen Ranavalona III on December 17, 1885, that granted France protectorate over the bay and its surrounding territory, plus the islands Nosy-Be and Ste.Marie de Madagascar.
The administration of the colony was subsumed into one of Madagascar in 1896. The 2nd Pacific Squadron of Imperial Russia was resupplied at Diego-Suarez on its way to the Battle of Tsushima 1905.
In 1942, Diego Suarez was the major objective of Operation Ironclad, the starting point of Allied invasion and Madagascar’s capture. The Allies were concerned Japan would force Vichy France into granting use of Madagascar, and determined the island shouldn’t be made a base for interdiction of Allied shipping. The initial invasion point was chosen to be Diego Suarez, with a concentration of government officials and its superlative harbor. The Japanese attacked by midget submarines on British naval forces, sinking an oil tanker and damaging Battleship HMS Ramillies.
France continued to use Antsiranana as a military base following Malagasy independence in 1960 and until the 1973 socialist revolution.