The Sultan of Siak was the ruler of the Siak Sultanate, a historical Malay state located in present-day Indonesia. Established in the 18th century, the sultanate played a significant role in regional trade and politics, particularly in the Riau Archipelago. The sultanate was known for its rich culture and contributions to the Malay language and literature. The sultanate's influence declined in the 19th century due to colonial pressures from the Dutch and British. Despite this, the legacy of the Sultan of Siak remains important in understanding the history of the Malay world and the impact of colonialism in Southeast Asia.