Although fighting in Pontiac's Rebellion began in 1763, rumors reached British officials as early as 1761. According to these rumors, discontented Native Americans were planning an attack. Senecas of the Ohio Country (Mingos) circulated messages ("war belts" made of wampum) which called for the tribes to form a confederacy and drive away the British. The Mingos, led by Guyasuta and Tahaiadoris, were concerned about being surrounded by British forts. Similar war belts originated from Detroit and the Illinois Country. The Native Americans were not unified, however, and in June 1761, Native Americans at Detroit informed the British commander of the Seneca plot. After William Johnson held a large council with the tribes at Detroit in September 1761, peace was maintained, but war belts continued to circulate. Violence finally erupted after the Native Americans learned in early 1763 that the French would give the "pays d'en haut" to the British.