In the early years of his reign, Pahang descended into turmoil, with various attempts made by the surviving sons of Tun Mutahir, based in Selangor, to overthrow him.

The civil wars that ravaged the land had led to the rise of dissension among the ruling class and territorial chiefs who were thenceforth divided into factions.

On 23 May 1836 at Pulau Maulana, Pekan, Che Puan Long, a wife of the 22nd Bendahara of the Johor Empire, Tun Ali, gave birth to a son Wan Ahmad, for whom an Arab, Habib Abdullah ibni Omar Al-Attas foretold he would lead a great future.

His elder brother, Tun Mutahir was supported by Johor to the south, and by the British Straits Settlements who were then opposing the Siamese Rattanakosin Kingdom.

Both sides, whose outside supporters had ulterior motives, engaged chiefly in raids and ambushes, with occasional battles near fortifications along the vast riverine system of Pahang.

The war ceased soon after Wan Ahmad's troops captured and established control over a number of important towns and regions in the interior, and eventually seized the capital, Pekan.

Tun Wan Ahmad transferred his executive and administrative powers to his eldest son Tengku Long Mahmud, in 1909 due to old age, retaining his position and titles as head of state until his death in 1914.