Tengku Yahya Petra was installed as the Sultan and ruler of the state of Kelantan on Sunday, 10 July 1960 granting him the title Sultan Yahya Petra replacing his father HRH Sultan Ibrahim ibni Almarhum Sultan Muhammad IV. Tengku Yahya Petra was born on 10 December, 1917 at Istana Balai Besar in Kota Bharu. He received his religious education during his childhood under the care of his uncle, Sultan Ismail.

Sultan Yahya Petra received his early education at the Francis Light School in Pulau Pinang when he was 14. After four years at the school he was sent to England by his uncle, Sultan Ismail in 1934 to further his studies.

Sultan Yahya Petra married Tengku Zainab binti Tengku Muhammad Petra when he was 22 years of age. The royal couple were blessed with a son and four daughters. His only son is the 28th Sultan of Kelantan, HRH Sultan Ismail Petra. His four daughters are HRH Tengku Mariam, HRH Tengku Rozan, HRH Tengku Salwani and HRH Tengku Rohani.

Sultan Yahya Petra was awarded the title of Tengku Temenggong and the Darjah Kerabat Yang Sangat Dihormati (D.K.) (The Most Honorable Royal Family Order) by Sultan Ismail on 21 July 1939. Sultan Yahya Petra was appointed to various main posts in the state government in order to familiarize him with administrative affairs. He was the Deputy President of the Council for Islamic Affairs and Malay Customs of Kelantan from 1941 until 1947. He was appointed the Assistant State Financial Officer on 2 April 1944 and Kota Bharu District Officer on 6 February 1945. In 1945 Sultan Yahya Petra was appointed Tengku Bendahara by his father HRH Sultan Ibrahim. On 31 December 1953, he was appointed the President of the Council for Islamic Affairs and Malay Customs.

When Sultan Yahya Petra was the Tengku Mahkota (Crown Prince), he was also involved in the affairs of the state and was concerned with the welfare of the people. During his reign, (1948 – 1960), when Kelantan was in a state of emergency, he did not hesitate to visit the remote villages of Kelantan.

On 5 June 1952, Sultan Yahya Petra received the Order of St. Michael and St. George (C.M.G.) from Queen Elizabeth II of England.

On the first anniversary of Independence of Malaya on 31 August 1958, Sultan Yahya Petra was appointed to the Seri Maharaja Mangku Negara (S.M.N.) Order - the highest Malayan award – by the first Yang di-Pertuan Agong His Majesty Seri Paduka Baginda Tuanku Abdul Rahman, the ruler of Negeri Sembilan. Sultan Yahya Petra also received other Royal Family Orders such as the Darjah Kerabat Yang Sangat Dihormati (the Most Esteemed Royal Family Order) from Brunei in 1961, Darjah Kerabat Terengganu (Royal Family Order of Terengganu) in 1964, Darjah Kerabat Selangor (Royal Family Order of Selangor) in 1966 and Darjah Kerabat Kedah (Royal Family Order of Kedah) in 1969. On 6 October 1966, Sultan Yahya Petra was made Colonel of the Malaysian Artillery Brigade.

On 22 July 1970, Sultan Yahya Petra was elected as Timbalan Yang di-Pertuan Agong by the Conference of Rulers. The oath-taking ceremony was performed on 21 September 1970. Then on 19 June 1975, the Conference of Rulers elected Sultan Yahya Petra, Yang di-Pertuan Agong. During his reign as the Yang di-Pertuan Agong, his son HRH Tengku Ismail Petra was the Regent of Kelantan.

Tengku Zainab binti Almarhum Tengku Mohamed Petra, who is the consort of Sultan Yahya Petra and the mother of the 28th Sultan of Kelantan, HRH Sultan Ismail Petra, was born on 7 August 1917. Tengku Zainab was taught religion by her father. She was also groomed on traditional Malay customs as well as royal customs inherited from one generation to another. She was also taught by several prominent religious teachers of Kelantan.

Tengku Zainab married Sultan Yahya Petra on 4 June 1939 and was given the title Tengku Ampuan Mahkota (conferred on the consort of the Crown Prince) by Sultan Ibrahim on 9 August 1956. On the same day she was conferred the S.P.M.K. Order. She was appointed as the Raja Perempuan (title of the consort of the Sultan) of Kelantan on 19 July 1960 and was given the title “Raja Perempuan Zainab II” on the day of the installation of Sultan Yahya Petra as the Sultan of Kelantan. Tengku Zainab was conferred the Darjah Kerabat (D.K. – Royal Family Order) on the first anniversary of Sultan Yahya Petra’s installation.

Tengku Zainab accompanied Sultan Yahya Petra on his official visits to several countries which gave her the opportunity to fulfill her responsibility as the Raja Perempuan and the Raja Permaisuri Agong. Tengku Zainab was a kind person who loved doing charity work. She was once the president of various social organizations such as the Girl Guides of Kelantan and the Women’s Institution.

Tengku Zainab gave special attention to ‘house-keeping’ such as decorating the palace and preparing food for the royal family. She also loved doing handicraft, collecting antiques and gardening. Tengku Zainab passed away on 10 January 1993 at the state palace at the age of 75 years old.