A cartridge includes a casing and a photosensitive drum rotatably supported in the casing. A rotatable driven coupling member is provided on an axial end of the photosensitive drum, with the driven coupling member including a driving force receiving portion for receiving a driving force to rotate the photosensitive drum. The driven coupling member is translatable with respect to the casing in a predetermined direction, which is substantially parallel to a rotational axis of the photosensitive drum, by a force received by a driven side abutment portion of the driven coupling member. A distance between the rotational axis of the driven coupling member and the driven side abutment portion is not more than a distance between the rotational axis of the driven coupling member and the driving force receiving portion.