Kaha IX

Kaha IX, era name Kerukunan (May 18, 1904 – February 16, 2000), birth name Yacob Ibrahim Osman al-Mustafa ibni Abdul Ahmed Kabir was the ninth and final king of the Cahaya dynasty. He ruled from 1916 to 1920, and was the shortest-reigning king of the dynasty.

Kaha IX's legacy in Cadasa is largely positive. Although he was loyal to the dynasty and monarchy, Kaha understood that things had to change in order to preserve the dynasty. His attempted transition of the country into a constitutional monarchy was foiled by brother Tunku Suliaman Fawaz and Kaha VIII consort Tengku Hadiyya. They placed him under house arrest in 1918, and the dynasty fell 2 years later.

Early life
Yacob Ibrahim Osman al-Mustafa ibni Abdul Ahmed Kabir, royal name Tunku Yacob Ibrahim, was born on May 18, 1904, in the Istana Petamakan, in Selamat, Cahaya dynasty. His father was Kaha VIII, and his mother was Tengku Yusra binti Ismail, one of the king's consorts. He had several half-brothers and sisters, and one brother, Suliaman Fawaz, whom he described as a "jealous" man, and they competed for their parents attention.

At age 10, the young prince was sent to Switzerland to attend the prestigious, as he was more academically gifted, while his brother was sent to the , furthering amplifying their rivalry.

He described his time there as "some of the best in my life." However, his studies were cut short at age 13, when he was forced to return to Cadasa due to his father's ailing health.

Reign (1916-1920)
On March 1, 1916, Kaha VIII died, and Kaha XI, the eldest son, became king. During his rule, he developed a plan for a legislature, created the office of prime minister, and engaged in talks with republicans to help the Cahaya dynasty transition into a constitutional monarchy. This enraged the conservatives, and Kaha XI brother Tunku Suliaman Fawaz and Kaha VIII consort Tengku Hadiyya placed him under house arrest in 1918, making him powerless. The dynasty fell 2 years later.

Later life
Kaha XI, now known by his abbreviated birth name Yacob bin Abdul Kabir, was elected to the Cadasan People's Assembly in 1939. He served as the Minister of Culture from 1939 to 1945.

On February 16, 2000, Kaha XI died of natural causes in his home.