General Thomas, in his zeal for the Begum Somroo's interests, raised up enemies for himself in the principal French and German officers. They took occasion to poison the Begum's mind against him by foul accusations; and in 1792 he was compelled to withdraw to Anopsheer, one of the frontier stations of the British army. Early in 1793, he took service under Appakandarow, a Mahratta chieftain. Le Vaissaux, or Levasso, a German adventurer, commanding the Begum's artillery, had always been Thomas's deadly foe, and was the leading man in driving him away. He possessed great military talents, and had rendered considerable services to his mistress; but he was a man of haughty, overbearing mien, and hated by all his brother-officers. Great was their indignation, though they were scarcely surprised, when the Begum, disregarding their remonstrances, and the advice, the all but commands, of the Emperor, surrendered her hand and heart to the German artilleryman, in 1793.
Begum Somroo, instigated by her husband, now determined to crush poor Thomas; and at the head of four battalions of foot, four hundred horse, and twenty pieces of cannon, she marched towards Jyjur, where he was stationed. But the Mahratta chiefs, who had long been jealous of her influence over Shah Aulem, stirred up a mutiny amongst the troops left in Serdhauna, and compelled her to return thither with all speed. The officers, to give a sanction to their proceedings, offered the jaghire to Zuffer Yab Khan, son of Somroo by a former wife. He was a young man of worthless and turbulent character; since his father's death he had lived in Delhi, receiving a handsome allowance from his step-mother.
It was only a few days after the marriage that this mutiny broke out. Zuffer, with a body of troops, rushed into Serdhauna, seized the town, and was proclaimed Jaghire Dar. The Begum vainly endeavoured to pacify her soldiers. She was arrested, together with her husband, and thrown into prison; and Le Vaissaux, too proud to sue for mercy, put an end to his own life.
In the course of the following year, the Begum, who had been ever since kept in durance vile, besought the assistance of George Thomas, for, said she, the hourly dread of assassination was driving her mad. Thomas was not deaf to her entreaties; he persuaded Bappoo, a Mahratta chief, to aid him with his forces, and together they marched upon Serdhauna. The Mahrattas were won over, partly by the prayers of Shah Aulem, and partly by liberal promises; and Zuffer having been expelled, the Begum was restored to power.