Lachit Borphukan was the son of Momai Tamuli Borbarua. Momai became first governor of upper Assam. He served Ahom army as commander in chief. Lachit enjoyed a nice upbringing and was educated in humanities, military science and scriptures.
Lachit got appointed as Borphukan of Stable of Royal Houses, Commander of the strategic Simulgarh Fort. Later he was appointed as scarf bearer of Ahem Swargadeo. He was appointed by King Chakradhwaj Singha to fight against Mughals to liberate Guwahati which he did successfully.
Battle of Saraighat:-
Once Mughals got defeated by army led by Lachit, Mughals army sailed Brahmaputra river towards Assam. They were approaching Guwahati as rebellious forces. Ram Singh 1 was the Commander in chief of Mughals. He sent a letter into Ahom camp which said that Lachit should leave Guwahati as he is paid 1 lakh. King started to doubt Lachit's devotion towards his kingdom. However, soon was made to realize that it was just a trick played by Mughals. In the last phase of Saraighat war, Assamese soldiers began to lose their will to continue the fight. However, Lachit continued fighting with complete patriotism as he felt that this was the task meant for him and he cannot disobey the orders given by the king. He boarded a boat and along with 7 other boats continued the battle on river Brahmaputra. He won the battle.
Ram Singh1 after losing battle mentioned words of appreciation and praise to Lachit Borphukan that how single handedly he led the war and won it. On Nov 24 each year, Lachit Divas is celebrated in Assam. His bravery was confined to state of Assam until recently when his statue was introduced to National Defense Academy in Khadakvasla Pune by Governor of Assam.