The Christian cross, seen as a representation of the crucifixion of Jesus on a large wooden cross, is a symbol of Christianity. It is related to the crucifix and to the more general family of cross symbols, the term cross itself being detached from the original specifically Christian meaning in modern English.
The Alexamenos graffito
The Sinai icon of Christ Pantocrator (6th century), showing Christ with a cruciform halo and holding a book adorned with a crux gemmata
An Eastern Catholic Syro-Malabar Major Archbishop with his blessing cross
The Vatican Obelisk in Rome
A cross is a geometrical figure consisting of two intersecting lines or bars, usually perpendicular to each other. The lines usually run vertically and horizontally. A cross of oblique lines, in the shape of the Latin letter X, is termed a saltire in heraldic terminology.
Bronze Age "wheel pendants" in the shape of the "sun cross" (Urnfield culture, 2nd millennium BC).
Early use of a globus cruciger on a solidus minted by Leontios (r. 695–698); on the obverse, a stepped cross in the shape of an Iota Eta monogram.