Our olive wood Jerusalem Cross, made in Jerusalem, is unique but goes back to the 11th and 12th centuries and is rich in symbolism. The Jerusalem Cross represents Christ's command to spread the Gospel around the world, a mission that started in Jerusalem. The 5 crosses have held different meanings, with the most popular being: 
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 centre Christianity (central cross) broadcast by missionaries to the four corners of the world
Five crosses to represent the five wounds of Jesus on the cross with the small crosses for his hands and feet, and the large central cross for the spear wound in His side.