Galatians
King James Version (KJV)

“And all the brethren which are with me, unto the churches of Galatia:”
King James Version (KJV)
1:2 And all the brethren - Who agree with me in what I now write.
Ga 1:2 And all the brethren which are with me. His fellow-laborers, such as Timothy, Titus, Silas, Luke, etc., some of whom at least were with him at this time. The word "all" implies that a number were with him. Unto the churches of Galatia. The inference from the language is that there were a considerable number scattered through the province.