We all know what a cross looks like, and yet when asked to describe one, the only valid answer is, "Which one?"
This page outlines a little bit about a cross which was quite possibly of the style used to crucify Jesus, and therefore revered by many Christians who refer to it as a Tau Cross. The heraldic name, however, is Crux Commissa.
The more widely known name, especially in a Christian context, is the Tau Cross (St. Anthony's Cross).
On his page we look at religious interpretations other than Christian, and you will notice there are several.
Heraldry is full of profound meaning, once we delve into it. Transliteration of Crux Commissa is 'commissioned cross'; that is, a cross that has been assigned a mission by a higher authority.
The horizontal bar at the top of the post, and the name, is rather like the auctoritate mihi commissâ (the square academic cap or 'mortarboard'), which originated from the priest's biretta, adopted as an Oxford University graduate's academic head dress, and more recently undermined by some US high schools.
With the cross bar used as a carrying handle, it is called Crux Ansata and represents a symbol of divinity on Egyptian and Assyro-Babylonian sculptures, such as Isis and Osiris. (See also the Ankh Cross.)
The Tau is an emblem of immortality and life in general. It is a Pagan sign of the mystic Tau of the Chaldeans and the Egyptians, where it represented the Roman god Mithras, the Greek Attis and their forerunner Tammuz, the Sumerian dying and rising god, consort of the goddess Ishtar.
Conveniently, the original form of the letter 'T' was the initial letter of the god of Tammuz. During baptism ceremonies, this cross was marked on the foreheads by the Pagan priest.
"Tau" appears in the name and shape of the astrological sign for the bull; a phallic symbol.
The Greek word for 'bull' is tauros and with a bit of imagination, you can see a bull's horns and snout in the 'T' shape; hence the astrological sign ♉ for 'Taurus the bull'.
In the Christian context, the mission is the Crucifixion, and the higher authority is God.