The appointment, however, rapidly erupted into a severe secession crisis in the royal house after it was contested by the crown prince, Tunku Bisnu.

Aiding to reconcile the two rivalling parties, the Siamese appointed Tunku Bisnu as the ruler of Setul, signifying the birth of Kedah into two separate realms.

[3] Tunku Bisnu spent most of his reign in Kedah in Setul, with local affairs being mainly administrated by his aide, Dato' Wan Abdullah.

Nonetheless, as recorded by Syair Sultan Maulana, it was narrated that Tunku Bisnu was a capable ruler that led the Kedahan troops during the war against the Burmese Konbaung dynasty forces in Salang (present-day Phuket, Thailand).

The crisis was predominantly derived from the sultan's refusal to appoint the crown prince to be the king of Kayang (Perlis) and Setul.

This resulted in Tunku Embun having to request military assistance from the governor of Ligor to overthrow the Kedahan government, falsely claiming that the sultan had allied with the British.

Following the fall of Kedah, Dato Wan Mad Ali was forced to move to Langkawi along with an exodus of 100 Malay families from Setul.

[2] The coup d'état led by Tunku Yaakob proved to be successful, as the sultan was forced to retreat to the British-backed Penang and later exiled in Malacca.

He and his son, Tunku Sulaiwan, were later brutally executed by the order of the Siamese king after he was found guilty of spreading malicious news of the previous sultan.

The partition was ratified by 1843, when Ahmad Tajuddin Halim Shah II, the sultan of Kedah, brought a royal entourage to the Siamese government in Bangkok.

Tunku Ismail also ordered the construction of a brick prison, enlarging the court, improving the telegram network and introducing the postal service.

His rule also witnessed a closer relationship with the Siamese, with the kingdom sending 260 individuals to subdue the Chinese rebellion of Phuket in 1878 together with the troops from Kedah and Perlis.

The vacant seat of the king led Kedah to appoint Tunku Baharuddin bin Ku Meh as governor for the administrative post in Setul.

[8]The appointment of Ku Din as the governor of Setul angered Tunku Muhammad, the crown prince, as he was supposed to rule the kingdom.

The king was replaced by a governor from Bangkok, Prak Khoja Ishak (Tui Bin Abdullah, later promoted to Phraya Smantaratthaburindra).

Today, only a small percentage of Thai Muslims in Satun are conversant in the language, a far-cry for her historical sister states down south.