Although Brant had planned on raiding German Flatts sooner than September, the absence of John Butler delayed his plans. Butler had returned to Fort Niagara after his attack on the Wyoming Valley communities in July, sending Captain William Caldwell to Unaquaga to recruit men for the unit known as Butler's Rangers. By early September it was clear that Butler was not returning to the area, so Brant and Caldwell launched the expedition with the men they had. The exact composition of the force that left Unadilla is unclear. Sources generally agree that 152 Iroquois, principally Mohawk, were in the force, but that the Loyalists (in either Caldwell's Ranger company or in Brant's company of volunteers) numbered between 200 and 300.