The Jerusalem Cross, also known as the Crusaders Cross and the Five-Fold Cross, is comprised of Greek and Tau crosses. Four Tau crosses meet in the center creating a Greek cross. Four additional Greek crosses, one in each corner, make a total of five crosses.
The symbolism of the five crosses has been explained in a variety of ways. Here are a few:
 

The five crosses represent the five wounds Jesus received on the cross. The large center cross represents the wound in Jesus' side while the four smaller crosses represent the wounds he received in his hands and feet.

The large center cross represents Jesus and the four smaller crosses represent the four Gospel writers. The four smaller crosses represent the four corners of the earth to which the gospel is being taken or for which Jesus died.

The five crosses represent the five nations active in the Crusades: Great Britain, France, Germany, Italy and Spain.

The five crosses represent the five principalities of the Latin Kingdom of Jerusalem. The Jerusalem Cross was employed as an emblem by the Crusaders.

Godfrey de Bouillon, who became the first ruler of Jerusalem after it was captured from the Moslems in 1099, wore the Jerusalem Cross as his symbol.

Jerusalem Cross: In year 1099  the Jerusalem Cross was  used as a coat of arms for the Latin Kingdom in Jerusalem. During the Crusades, it was referred to as the "Crusaders Cross". The four small crosses are symbolic of the four Gospels proclaimed to the four corners of the earth, beginning in Jerusalem; the large cross symbolizes the person of Christ. Godfrey de Bouillon, who became the first ruler of Jerusalem after it was captured in 1099, wore the Jerusalem Cross as his symbol.

”. . . and anyone who does not take his cross and follow me is not worthy of me. Whoever finds his life will lose it, and whoever loses his life for my sake will find it.” Matthew 10:38-39