I saw the beast - See the notes on Revelation 12 (note), Revelation 13 (note) and Revelation 17 (note).
And the kings of the earth, and their armies, gathered together - There is allusion here to the same assembling of hostile forces which is described in Revelation 16:13-14, for the great decisive battle that is to determine the destiny of the world - the question whether the Messiah or antichrist shall reign. There can be no doubt that the writer in these passages designed to refer to the same events - the still future scenes that are to occur when the Roman, the pagan, and the Muhammedan powers shall be aroused to make common cause against the true religion, and shall stake all on the issue of the great conflict. See the notes on Revelation 16:13-14.
Against him that sat on the horse - The Messiah - the Son of God. notes on Revelation 19:11.
And against his army - The hosts that are associated with him - his redeemed people. See the notes on Revelation 19:14.