Calvary Cross. This form of cross does not date from Christianity. It was known and used for mystical purposes, thousands of years before our era. It formed part and parcel of the various Rituals, in Egypt and Greece, in Babylon and India, as well as in China, Mexico, and Peru. It is a cosmic, as well as a physiological (or phallic) symbol. That it existed among all the “heathen” nations is testified to by Tertullian. “How doth the Athenian Minerva differ from the body of a cross?” he queries. “The origin of your gods is derived from figures moulded on a cross. All those rows of images on your standards are the appendages of crosses; those hangings on your banners are the robes of crosses.” And the fiery champion was right. The tau or T is the most ancient of all forms, and the cross or the tat (q.v.) as ancient. The crux ansata, the cross with a handle, is in the hands of almost every god, including Baal and the Phœnician Astarte. The croix cramponnée is the Indian Swastica. It has been exhumed from the lowest foundations of the ancient site of Troy, and it appears on Etruscan and Chaldean relics of antiquity. As Mrs. Jamieson shows: “The ankh of Egypt was the crutch of St. Anthony and the cross of St. Philip. The Labarum of Constantine . . . was an emblem long before, in Etruria. Osiris had the Labarum for his sign; Horus appears sometimes with the long Latin cross. The Greek pectoral cross is Egyptian. It was called by the Fathers the devil’s invention before Christ . The crux ansata is upon the old coins of Tarsus, as the Maltese upon the breast of an Assyrian king ...The cross of Calvary, so common in Europe, occurs on the breasts of mummies. . . it was suspended round the necks of sacred Serpents in Egypt. . . . Strange Asiatic tribes bringing tribute in Egypt are noticed with garments studded with crosses, and Sir Gardner Wilkinson dates this picture B.C. 1500.” Finally, “Typhon, the Evil One, is chained by a cross”.(Eg. Belief and Mod. Thought).
Source: H.P.Blavatsky - The Theosophical Glossary