He was the eldest son of Sardar Charat Singh and Sardarni Desan Kaur Warraich.
Upon the death of his father, Charat Singh, he succeeded to the leadership of the Sukerchakia Misl.
He is known for his alliance with Jassa Singh Ramgarhia and for reducing the power of the Kanhaiya Misl.
[6] Maha Singh was brought him up in his family's martial tradition by his parents and accompanied his father to a variety of military expeditions from an early age.
Desan Kaur was a worldly-wise, experienced, courageous and an intelligent lady, her people were content with her admiration skills.
[13] Soon Maha Singh captured the Rohtas Fort from Nur-ud-din Bamezai, a general of Ahmad Shah Durrani and occupied Kotli Ahangaran, near Sialkot.
After this victory, he laid a four-month siege to Rasool Nagar assisted by Jai Singh Kanhaiya.
[7] He triumphed over Pir Muhammad, the ruler of the Chathas, on the eastern bank of river Chenab who surrendered to Maha Singh.
[7][14] While he was at battle, Raj Kaur affectionately known as Mai Malwain gave birth to their only son.
Mahan Singh distributed grains to every body who approached him, it was said that his good will was the reason behind the recovery of his son from smallpox.
Jai Singh's pride was humbled but he agreed for the match and in 1786 the young children were engaged.
This alliance proved very helpful to Ranjit Singh in his future conquests and consolidation of Punjab under his sway.
During the siege of Sodhra, which was being occupied by the Bhangi Misl, he contracted dysentery[2] The ambitious Sukarchakia chief was having a failing health due to overwork and exhaustion and in the course of the siege of Sodhra when the victory was just insight he was suddenly taken ill by a violent attack of fever.
[16] According to Hari Ram Gupta,[26] "There is not the least doubt about it that if he had lived ten years longer, he would have become the sole monarch of the whole of northern India from the Khyber Pass to the Ganga, and from the Himalayas to the Arabian sea, and Emperor Shah Alam II would have become his protege.
"Muhammad Latif states,[27]"Mahan Singh was brave, enterprising and prudent beyond his years; and the age in which he lived highly favoured his ambitious schemes His early feats in arms had acquired for him so great a reputation that many influential independent Sardars joined his banner.