Jamieson, Fausset and Brown on Revelation 6:2

2. Evidently Christ, whether in person, or by His angel, preparatory to His coming again, as appears from Re 19:11, 12.

bow--(Psa 45:4, 5).

crown--Greek, "stephanos," the garland or wreath of a conqueror, which is also implied by His white horse, white being the emblem of victory. In Re 19:11, 12 the last step in His victorious progress is represented; accordingly there He wears many diadems (Greek, "diademata"; not merely Greek, "stephanoi," "crowns" or "wreaths"), and is personally attended by the hosts of heaven. Compare Zec 1:7-17; 6:1-8; especially Re 6:10 below, with Zec 1:12; also compare the colors of the four horses.

and to conquer--that is, so as to gain a lasting victory. All four seals usher in judgments on the earth, as the power which opposes the reign of Himself and His Church. This, rather than the work of conversion and conviction, is primarily meant, though doubtless, secondarily, the elect will be gathered out through His word and His judgments.