Sir Maharaja Yadavindra Singh Mahendra, the ninth and last Maharaja of Patiala, was born on 7 January 1914, in Patiala.

He had studied in the Aitchison College, Lahore. He worked for the Patiala State Police and got promoted to Inspector General. He had also played for the Indian Cricket Team and played one Test match in 1934. 

He succeeded his father, Maharaja Bhupinder Singh on 23 March 1938.  

Sir Maharaja Yadavindra Singh Mahendra visited Qadian on 14 April 1941. He arrived in the city by car in the afternoon, along with his personal staff. Hazrat Syed Zainul Abidin Valiullah Shah (ra), Nazir Umur-e-Ama (Director of Public Affairs) welcomed the distinguished guest. Sir Yadavinder Singh stayed in the house of Hazrat Sir Chaudhry Muhammad Zafrulla Khan (ra). On the same day, after Asr prayers, Hazrat Mirza Bashiruddin Mahmud Ahmad (ra), Khalifatul Masih II, invited the Maharaja for tea. Hazrat Chaudhry Zafrulla Khan (ra) and some other respectable guests were also invited. 

In the evening, Hazrat Chaudhry Zafrulla Khan (ra) held a dinner in honour of the Maharaja. Hazrat Khalifatul Masih II (ra) also blessed the occasion. 

The next day, on 15 April, Maharaja Yadavindra Singh was shown various institutions of the Ahmadiyya Jamaat, including Talim-ul-Islam High School, Noor Hospital, Madrasa-e-Ahmadiyya, Bahishti Maqbarah, Aqsa Mosque, Qasr-e-Khilafat, and Sadiq Library.

Maharaja Yadavindra Singh was then given a biography of the Holy Prophet (sa) which was published in the Gurmukhi language. 

Sir Maharaja Yadavindra Singh Mahendra passed away on 17 June 1974.