[citation needed] During his reign, he was known for being an intelligent and respectable ruler of Sulu, as well as an advocate of the Sharia Law in his domains.
Moro raids began to frequent during his reign, with slave-raiding parties from many of his subjects across Sulu beginning to terrorise and ravage the coasts of the Philippines and its environs.
During his father's reign, Sulu gained de facto independence and trading rights from the Bruneian Empire.
Whichever date is true, what is known as fact is that he was crowned and proclaimed Sultan almost immediately after his father's death.
His reign saw little reform in the Sulu ruling and kinship system which was established nearly a century ago by his ancestors.
Sultan Tengah used this economic rise to his advantage, winning over numerous chiefs and subordinate rulers to his side.
He was also considered a "tidy" ruler, who kept himself clean and presentable to any chief, this reflected the situation of the young state, who had to prove to its benefactor Brunei, that it was capable of self-governance, and to show a cultured face to the intruding Spaniards, who have opted to make war with the Sulus.
The marrying off of a female member of the family to another was a known gesture, indicating the superiority of the receiving party in those days.
[1] When Sultan Tengah ascended to the throne around 1596, the Spaniards sent an expedition once again to make war with Sulu.
[1] In November 1596, the Manila Spanish government sent Juan Ronquillo to build a fortified military garrison in Tampakan to thwart Moro slave raids that began to escalate in number and severity, as Sulu's maritime power increased.
This was the last major expedition sent by the Spaniards during Sultan Tengah's reign, marking the end of the first phase of the Spanish-Moro wars.
After the Spaniards' last ill-fated expedition, Muwallil Wasit was called back to Brunei where his family was and Sultan Tengah continued to protect his throne from his cousin and usurper.
However, Sultan Tengah, more beloved by his people and favoured by Brunei, maintained the throne and continued to rule Sulu prosperously.