[2] On the outbreak of the war with "King Philip", the Grand Sachem of the Wampanoag Confederacy, in June 1675, two companies of militia were raised by order of the Boston Council.

King Philip's War came to an end with the death of Philip on 12 August 1676 at the hands of Captain Benjamin Church, but during the year of its continuance many sharp and bloody skirmishes were fought, in most of which Mosley took a distinguished part, more especially in the capture and destruction, on 19 December 1675, of Canonicut, a fortified encampment to the west of Rhode Island.

He is said, for instance, to have made an unprovoked raid on a mission at Marlborough, to have plundered and beaten the disciples, and to have driven eleven of them, including six children, three women, and one old man, into Boston.

[4] But another clergyman, not connected with the mission, declared that Mosley merely arrested at Marlborough eleven Indians who were reasonably suspected of murdering a white man, his wife, and two children at Lancaster, some nine miles off.

[5] Mosley is said to be the original hero of the story of the man who scared the Indians by taking off his wig and hanging it on the branch of a tree, in order that he might fight more coolly.