of the war The war began in January 1767 when the Marathas, possibly anticipating movements by the nizam, invaded northern Mysore. They reached as far south as the Tunghabadhra River, before Haider entered into negotiations to end the invasion. In exchange for payments of 30 lakhs rupees the Marathas agreed to withdraw north of the Kistna River; by March, when the nizam began his invasion, they had already withdrawn. According to Mysore historian Mark Wilks, this action by the Marathas was a somewhat typical move to acquire wealth that might otherwise be claimed by other belligerents. The nizam advanced as far as Bangalore, accompanied by two battalions of company troops under Colonel Joseph Smith. In May, Smith discovered that the Haider and the nizam were negotiating an alliance, and consequently withdrew most of his troops to the Carnatic frontier. The deal struck between the two powers called for them to join against the British. Haider was to pay 18 lakhs rupees for the invasion to end, and the nizam was to recognise Haider's son Tipu Sultan as Nawab of the Carnatic once that territory was conquered. Despite the agreement the two sides exhibited little trust for one another; Haider was known to place spies in the nizam's camp. This diplomatic manoeuvring resulted in an attack against a company outpost at Changama by the combined Mysore-Hyderabad army under Hyder's command. Despite significantly outnumbering the British force (British estimates place the allied army size at 70,000 to the British 7,000), the allies were repulsed with heavy losses. Haider moved on to capture Kaveripattinam after two days of siege, while Colonel Smith, who commanded at Changama, eventually retreated to Tiruvannamalai for supplies and reinforcements. There Haider again attacked, and was decisively repulsed on 26 September 1767. With the onset of the monsoon season, Haider opted to continue campaigning rather than adopting the usual practice of suspending operations because of the difficult conditions the weather created for armies. After overrunning a few lesser outposts, he besieged Ambur in November 1767, forcing the British to resume campaigning. The British garrison commander refused large bribes offered by Haider in exchange for surrender, and the arrival of a relief column in early December forced Haider to lift the siege. He retreated northward, covering the movements of the nizam's forces, but was disheartened when an entire corps of European cavalry deserted to the British. The failures of this