Badar Singh, the great-grandson of Sada Singh, married the daughter of a petty sardar of the district. Their son Jassa Singh Ahluwalia was born in 1718. Jassa Singh was barely five years old when his father died in 1723. Subsequently his mother requested Mata Sundri, the widow of Sikh Guru, Guru Gobind Singh to take care of young Jassa.
Upon growing up, she put him under the care of Sikh leader Nawab Kapur Singh. Jassa Singh soon rose in ranks and, on the eve of his death, Kapur Singh appointed him his successor in 1753. And after the capture of Lahore in 1761, Khalsa honored him with the title of Sultan-ul-Qaum (King of the whole people). He was the first one to take on the surname Ahluwalia (or Walia nowadays) and his followers use the surname Walia or Ahluwalia. He founded the state of Kapurthala in 1772, and his descendants remained powerful chiefs in Punjab until the rise of Ranjit Singh (1780–1839).
Jassa Singh had no male heir (two daughters) and, upon his death in 1783, he was cremated at Burj Baba Atal Sahib; he was succeeded by his cousin, Bhag Singh.