Stringer Lawrence appears to have entered the army in 1727 and served in Gibraltar and Flanders, thereafter participating in the Battle of Culloden. In 1748 he went out to India to command the troops of the East India Company, with the rank of major and the prestige of an accomplished soldier. Dupleix 's plans for the French conquest of southern India were about to take effect and Lawrence was actively engaged not long after his arrival at Fort St David.He successfully foiled an attempted ambush by French troops at Cuddalore, but was captured at Ariancopang (modern Ariankuppam) by a French cavalry patrol while leading forces to support Admiral Edward Boscawen in enforcing the 1748 Siege of Pondicherry. The French had held him prisoner until Aix-la-Chapelle 's peace.
He was in command at Devicota 's capture in 1749, during which one of his subordinate officers was Robert Clive (1725–1774), the future Commander-in - Chief of British India, with whom he began a lifelong friendship. When Clive became popular, he respected Lawrence by refusing to accept an honorable sword unless, as the founder of the Indian army, one was also voted for him.
Lawrence returned to England in 1750 but, by 1752, he was back in India. Here he found Clive in command of a force destined for Trichinopoly's relief. As senior officer Lawrence took control of the command, but was careful to allow Clive every credit for his share in subsequent operations, which included Trichinopoly's relief and the surrender of the entire French siege force. He defeated the French at Bahur in 1752 with an inferior army, and again relieved Trichinopoly in 1753.He fought a series of actions to defend that place for the next seventeen months, and finally arranged a three-month armistice, later converted into a conditional treaty. He was commander-in - chief until the first detachment of the crown's regular forces has arrived.
He served in the operations against Wandiwash in 1757, and was in command of Fort St George, Madras, during the French siege under Lally, in 1758-1759. He was compelled to return to England in 1759 by failing health, but he resumed his command as major general and commander-in - chief in 1761. Clive supplemented the limited income of his old friend by settling an annuity of £ 500 per year on him. He presided over the board charged with arranging the reorganization of the Madras army in 1765 and he finally retired the next year.