The Four Horsemen of the Apocalypse are figures in the Book of Revelation in the New Testament of the Bible, a piece of apocalypse literature written by John of Patmos. They are not specifically identified in the Bible, but subsequent commentary often identifies them as Conquest, War, Famine, and Death. The Four Horsemen are the first in a series of "Seal" judgments, which is when God will judge the Earth and give humans a chance to repent before they die.

It is important to note that the term "Four Horsemen" can also be used metaphorically to describe communication styles that can predict the end of a relationship, such as criticism, contempt, defensiveness, and stonewalling. However, this is not related to the biblical Four Horsemen of the Apocalypse.

In summary, the Four Horsemen refer to four aspects of Gods judgment that will pour out on the earth at the beginning of the Tribulation, and they are identified as Conquest, War, Famine, and Death.