Apparently it was a dispute with the Indians which caused the first temporary breach between Bacon and Berkeley. We do not know just what happened, but Bacon in a letter to the Governor speaks of his "unbecoming deportment in your Honor's presence," and said he was sorry for it. Sir William's reply makes it probable that Bacon had suffered some losses from neighboring Indians, and had retaliated. "This sudden business of the Indians," Berkeley said, had raised in him "high distemper." And he asked Bacon to consider that relations between the whites and the Indians was his responsibility, so that it was important that he be advised of all dealings with them. Should there be serious trouble he would be criticised both in England and Virginia.
Bacon must have resented Berkeley's monopoly of the fur trade. He tells us that a desire to have a share in this lucrative business had been one of his motives for settling on the frontier. But he made a virtue of necessity and, in partnership with his neighbor, William Byrd I, applied to the governor for a license. They would pay him 800 pounds of beaver fur for the first year and 600 pounds a year thereafter. This looked good to Sir William. "I am in no such plentiful condition that I should refuse a good offer," he replied, "and therefore am likely to accept your and my cousin Byrd's offer."
With the opening months of 1676 there were ominous rumblings of revolt. From New England came word that the English there were engaged in a deadly war with the Indians, which Berkeley thought was not merely a local affair, "but a general combination of all from New England thither." The so-called allied tribes on the Virginia frontiers were sullen and resentful. "They also would be rid of us if they could," said Berkeley. Their efforts to wipe out the English in previous wars had failed only because their bows and arrows were no match for the muskets of the English. Now that they had firearms might not their efforts be more successful?
It was the Marylanders who had given firearms to the Susquehannocks, a fierce tribe living on their northern border. This they did so that they could protect them from the Senecas, one of the tribes of the Iroquois confederation. But in 1674, when the Marylanders made a separate treaty with the Senecas, the latter fell on the Susquehannocks, defeated them in battle, and swept them out of their fortified villages. Fleeing through Maryland the remnant of the tribe established themselves on the north bank of the Potomac directly across from the site of Mount Vernon.