Aceh Sultanate in the context of "Pagaruyung Kingdom"

The Ottoman expeditions to Aceh were dispatched in 1566 and the following years by the Ottoman Empire in support of the Aceh Sultanate in its fight against the Portuguese Empire in Malacca. The Ottomans primarily helped the Acehnese produce cannons, but there are some signs of military support as late as 1585. The expeditions were sparked by an envoy sent by the Acehnese Sultan Alauddin Riayat Syah al-Kahhar (1539–71) to Suleiman the Magnificent in 1564, and possibly as early as 1562, requesting Ottoman support against the Portuguese. The expeditions formed the basis of the nineteenth-century Achenese claim to be a dependency of the Ottoman Empire.

Alauddin Ri'ayat Syah al-Kahar (died 29 September 1571) was the third Sultan of the Aceh Sultanate, reigning from either 1537 or 1539 until his death. He is considered to be one of the strongest rulers in the history of the sultanate and greatly strengthened Aceh. Alauddin's reign was marked by increased conflict with the Portuguese and their Malay and Sumatran allies and his dispatching of envoys to the Ottoman sultan, Suleiman the Magnificent in the 1560s.

Malacca City (Malay: Bandaraya Melaka or Kota Melaka) is the capital city of the Malaysian state of Malacca. It is the oldest Malaysian city on the Straits of Malacca, having become a successful entrepôt in the era of the Malacca Sultanate. The present-day city was founded by Parameswara, a Sumatran prince who escaped to the Malay Peninsula when Srivijaya fell to the Majapahit. Following the establishment of the Malacca Sultanate, the city drew the attention of traders from the Middle East, South Asia, and East Asia, as well as the Portuguese, who intended to dominate the trade route in Asia. After Malacca was conquered by Portugal, the city became an area of conflict when the sultanates of Aceh and Johor attempted to take control from the Portuguese.

Following a number of wars between these territories, Aceh declined in influence while Johor survived and expanded its influence over territory previously lost to Aceh in Sumatra when Johor co-operated with the Dutch to take Malacca from the Portuguese who arrived to establish dominance over Java and Maluku Islands. However, due to royal internal strife between the Malay and Bugis, the Johor-Riau Empire was divided into the sultanates of Johor and Riau-Lingga. This separation became permanent when the British arrived to establish their presence in the Malay Peninsula. The Dutch, who already felt threatened in the presence of the British, began conquering the Riau-Lingga Sultanate along with the rest of Sumatra, while Johor came under British influence following the signing of the Anglo-Dutch Treaty of 1824.