Mughal Empire. Aden in Yemen was captured by the Ottomans in 1538, in order to provide an Ottoman base for raids against Portuguese possessions on the western coast of the Mughal Empire. Sailing on, the Ottomans failed against the Portuguese at the siege of Diu in September 1538, but then returned to Aden, where they fortified the city with 100 pieces of artillery. From this base, Sulayman Pasha managed to take control of the whole country of Yemen, also taking Sana'a. With its strong control of the Red Sea, Suleiman successfully managed to dispute control of the trade routes to the Portuguese and maintained a significant level of trade with the Mughal Empire throughout the 16th century. From 1526 until 1543, Suleiman stationed over 900 Turkish soldiers to fight alongside the Somali Adal Sultanate led by Ahmad ibn Ibrahim al-Ghazi during the Conquest of Abyssinia. After the first Ajuran-Portuguese war, the Ottoman Empire would in 1559 absorb the weakened Adal Sultanate into its domain. This expansion furthered Ottoman rule in Somalia and the Horn of Africa. This also increased its influence in the Indian Ocean to compete with the Portuguese Empire with its close ally, the Ajuran Empire. In 1564, Suleiman received an embassy from Aceh (a sultanate on Sumatra, in modern Indonesia), requesting Ottoman support against the Portuguese. As a result, an Ottoman expedition to Aceh was launched, which was able to provide extensive military support to the Acehnese. The discovery of new maritime trade routes by Western European states allowed them to avoid the Ottoman trade monopoly. The Portuguese discovery of the Cape of Good Hope in 1488 initiated a series of Ottoman-Portuguese naval wars in the Ocean throughout the 16th century. The Ajuran Sultanate allied with the Ottomans defied the Portuguese economic monopoly in the Indian Ocean by employing a new coinage which followed the Ottoman pattern, thus proclaiming an attitude of economic independence in regard to the Portuguese. Mediterranean and North Africa Having consolidated his conquests on land, Suleiman was greeted with the news that the fortress of Koroni in Morea (the modern Peloponnese, peninsular Greece) had been lost to Charles V's admiral, Andrea Doria. The presence of the Spanish in the Eastern Mediterranean concerned Suleiman, who saw it as an early indication of Charles V's intention to rival Ottoman dominance in the region. Recognizing the need to reassert naval preeminence in the Mediterranean, Suleiman appointed