Revelation 6:8

And I saw, and behold a pale horse — Suitable to pale death, his rider. And hades — The representative of the state of separate souls. Followeth even with him — The four first seals concern living men. Death therefore is properly introduced. Hades is only occasionally mentioned as a companion of death. So the fourth seal reaches to the borders of things invisible, which are comprised in the three last seals. And power was given to him over the fourth part of the earth — What came single and in a lower degree before, comes now together, and much more severely. The first seal brought victory with it: in the second was "a great sword;" but here a scimitar. In the third was moderate dearth; here famine, and plague, and wild beasts beside. And it may well be, that from the time of Trajan downwards, the fourth part of men upon the earth, that is, within the Roman empire, died by sword, famine, pestilence, and wild beasts. "At that time," says Aurelius Victor, "the Tyber overflowed much more fatally than under Nerva, with a great destruction of houses and there was a dreadful earthquake through many provinces, and a terrible plague and famine, and many places consumed by fire." By death — That is, by pestilence wild beasts have, at several times, destroyed abundance of men; and undoubtedly there was given them, at this time, an uncommon fierceness and strength. It is observable that war brings on scarcity, and scarcity pestilence, through want of wholesome sustenance; and pestilence, by depopulating the country, leaves the few survivors an easier prey to the wild beasts. And thus these judgments make way for one another in the order wherein they are here represented.

What has been already observed may be a fourfold proof that the four horsemen, as with their first entrance in the reign of Trajan, (which does by no means exhaust the contents of the four first seals,) so with all their entrances in succeeding ages, and with the whole course of the world and of visible nature, are in all ages subject to Christ, subsisting by his power, and serving his will, against the wicked, and in defence of the righteous. Herewith, likewise, a way is paved for the trumpets which regularly succeed each other; and the whole prophecy, as to what is future, is confirmed by the clear accomplishment of this part of it.