In Hikayat Siak it is mentioned that the Sultanate of Siak Sri Indrapura was established by Raja Kechil (1699-1746), the title of Sultan Abdul Jalil Rahmat Shah I son of King Johor (Sultan Mahmud Shah), and his wife Encik Pong. Its people were called Malay Minangkabau people.
Until the emergence of Raja Kechil in the early eighteenth century, Siak's coastal areas were largely under the domination of the sultanates on the Malay peninsula, first Melaka and then Johor, although they were ruled by an elite originating in Sumatra's central highlands.
The center of the Siak kingdom is in Buantan. The name of Siak was allegedly derive from the name of a type of vegetation that is widely available there.
Raja Kecil was the figure most responsible for merging the east coast societies into the loosely structured Siak sultanate, and he and his descendants dominated Siak's history throughout the eighteenth century. He succeeded in developing the kingdom.
In 1717, Raja Kechil became powerful and managed to seize the throne of Johor. In 1722 the Kingdom of Johor was recaptured by Tengku Sulaiman, Raja Kecik’s in-law, who was the son of Sultan Abdul Jalil Riayat Shah.
The last sultan of Siak was Sultan Syarif Kasim I, who was in throne from 1915 to 1945. He declared the allegiance to the Government of the Republic of Indonesia.
Minangkabau of Siak