Hazrat Maulvi Rahmat Ali (ra) was the son of Hazrat Muhammad Hassan (ra). 

Hazrat Muhammad Hassan (ra) was very passionate to devote his son for the service of Islam Ahmadiyyat.

Hazrat Maulvi Rahmat Ali (ra) had not yet completed his primary education when his father sent him to Madrasa-e-Ahmadiyya with the written permission from Hazrat Mirza Ghulam Ahmad (as), the Promised Messiah.

When Hazrat Maulvi Rahmat Ali (ra) passed the Maulvi Fazil exam, his request for life devotion was accepted by Hazrat Mirza Bashiruddin Mahmud Ahmad (ra), Khalifatul Masih II. Huzoor (ra) instructed him to go to Indonesia to establish the Ahmadiyya mission there.

On 17 August 1925, Hazrat Maulvi Rahmat Ali (ra) departed for Indonesia and reached Sumatra in September. Despite landing in a foreign place, his resolve overcame all possible barriers. He learnt the language, began preaching and soon started discussions and debates with the local Muslim ulema (religious clergy). He established the first jamaat within a few months, with eight people performing bai‘at.

Hazrat Maulvi Rahmat Ali (ra) served in Indonesia for four years and returned to Qadian in 1930. After some months, Huzoor (ra) instructed him to go to Indonesia again. He then returned to Qadian in 1936. 

The next year, he went to Indonesia again, upon Huzoor's (ra) instruction.
In 1939, he came to Qadian on the occasion of Khilafat Jubilee and then left for Indonesia again. 

After serving in Indonesia for a long time, Hazrat Maulvi Rahmat Ali (ra) returned to Qadian in 1950.