God said He would send four destroyers against Jerusalem:
“I will send four kinds of destroyers against them,” declares the LORD, “the sword to kill and the dogs to drag away and the birds and the wild animals to devour and destroy.”1Jer 15:3
The four horses in Revelation 6 are the four destroyers sent against the errant in the kingdom of God.
The first is a white horse, representing the Angel of God, who brings pestilence and wild beasts.
The second, a red horse, brings war. He was announced by the second living creature, the ox who was sacrificed for “a time, times, and half a time.” There was no war until the time of the second living creature. The “time, times, and half a time” of the second living creature ended in 1471.
The third living creature, a man, announces a black horse and “scales that go out of balance”: the economic collapse of the financial system. In 1494, the Italian Medici Bank, which invented the modern accounting system of debits and credits, became the first big bank to “go out of balance.”
The fourth and final creature is a green horse, representing death and Hades. Some translate chloros as ashen, but it is translated into “green” elsewhere, including in Revelation 8:7 and 9:4. We will see that there is a reason for the color green here.
These four horses were “given authority over a fourth of the Earth.” Europe was the fourth of the Earth that represented Christianity until the 16th century. Europe represented those north and west of Jerusalem, the initial ground of Christianity.
Europe’s greatest enemy was Islam. Its flags of white, red, black, and green were the colors of the four horses that terrorized Europe for 1,000 years. Daniel described the pope’s fight against Islam by saying, “He will act against the strongest of fortresses.”2Dan 39:12 The fortresses of Islam were the strongest in the world, surrounded by double and sometimes triple walls and protected by ample moats.3crusader-castles.com