Like the Chi Rho symbol, the Jerusalem Cross is a symbol with which many Catholics are familiar, but may not know the meaning. The symbol's origins are unclear- but was widely seen when the first crusaders used it on their coat of arms. At this time, it became known as the Crusaders' Cross. The Knight's Templar, an elite order of crusaders who built many of the medieval structures in Israel, used this symbol throughout their churches from the 11th through the 13th centuries.
The Cross has a very rich symbolism. The three different meanings of the five crosses are:
- A combination of the Old Testament teachings (the four Tau Crosses) and the New Testament teachings (the four Greek Crosses)
- The four evangelists, Matthew, Mark, Luke and John, with Christ in the center Christianity (central cross) broadcast by missionaries to the four corners of the world
- Five crosses representing the five wounds of Jesus on the cross (small crosses for the hands and feet, and the large central cross for the spear wound in His side. (taken from here)