The place was named for Diogo Soares, a Portuguese navigator who visited the bay in 1543. In the 1880s, the bay was coveted by France, which desired it as a coaling station for steamships. After the first Franco-Hova War, Queen Ranavalona III signed a treaty on December 17, 1885 giving France a protectorate over the bay and surrounding territory, as well as the islands of Nossi-Be and Ste. Marie de Madagascar.
The colony's administration was subsumed into that of Madagascar in 1896.
The Second Pacific Squadron of Imperial Russia anchored and was resupplied at Diego-Suarez on its way to the Battle of Tsushima in 1905.
Diego Su�rez was one of the points of invasion for Allied forces when they captured Madagascar during 1942. There were fears that Japan would pressure Vichy France into granting use of Madagascar in much the same way as French Indo-China during the previous year. Consequently an invasion of the island was launched. Diego Suarez was selected as the initial invasion point due to its superlative harbour and the fact that it was the seat of many important officials. This was also the site of an attack by Japanese midget submarines on the British fleet.
France continued to use the city as a military base after the Malagasy independence 1960 until the socialist revolution of 1973
