The Ottoman–Portuguese or Turco-Portuguese confrontations refers to a series of different military encounters between the Portuguese Empire and the Ottoman Empire, or between other European powers and the Ottoman Empire in which relevant Portuguese military forces participated. Some of these conflicts were brief, while others lasted for many years. Most of these conflicts were in the Indian Ocean, in the process of the expansion of the Portuguese Empire. These conflicts also involved regional powers, after 1538 the Adal Sultanate, with the aid of the Somali Ajuran Empire and the Ottoman Empire, fought against the Ethiopian Empire. The Ethiopians were supported by the Portuguese, under the command of Cristóvão da Gama, the son of the famous explorer Vasco da Gama. This war is known as the Ethiopian–Adal war.