Hyder Ali then raised additional forces in Mysore and went on the offensive. In November 1768 he split his army into two, and crossed the ghats into the Carnatic, regaining control of many minor posts held by the British. En route to Erode Hyder Ali overwhelmed one contingent of British, who were sent as prisoners to Seringapatam when it was established that one of its officers was serving in violation of a parole agreement. After rapidly establishing control over much of the southern Carnatic, his march approached Madras. This prompted the British to send an envoy to discuss peace; because of Hyder Ali's insistence that the Nawab of the Carnatic be excluded from the negotiations, they went nowhere. Hyder Ali then surprised Company authorities by taking a picked force of 6,000 cavalry and a small number of infantry, and made in three days a forced march of to the gates of Madras.