(also known as ansate cross.)
supposedly, the ankh is the precursor to the christian cross. the ankh represents the union of man and woman (Osiris and Isis), and thus heaven and earth. when the christians got hold of it, they effectively cut out the female component by lopping off the circle of the ankh. this coincides with the theory that early christianity contained a holy trinity of man, woman and child, which was later amended to the more familiar Father, Son, and Holy Spirit.