A saltire, also called Saint Andrew's Cross or the crux decussata, is a heraldic symbol in the form of a diagonal cross. The word comes from the Middle French sautoir, Medieval Latin saltatoria.
Coin of Theodosius II (425–429), showing the emperor with globus cruciger and with the same vexillum
Saint Andrew martyred on a decussate cross (miniature from an East Anglian missal, c. 1320)
Quarterly 1st & 4th: Barry of six [seven] vair and gules; 2nd & 3rd: Gules, a saltire vair (Henry Beaumont of Devon, d.1591)
Papal coat of arms for Pope Innocent VIII with the Keys of Peter saltirewise (Wernigerode Armorial, c. 1490)
Saint Patrick's Saltire or Saint Patrick's Cross is a red saltire on a white field. In heraldic language, it may be blazoned argent, a saltire gules. Saint Patrick's Flag is a flag composed of Saint P
Insignia of a Knight of St Patrick: Gold crowns on a green shamrock on a red Cross of Saint Patrick
Uniform and colonel's flag of the Regiment of Hibernia in Spanish service, mid-18th century
St Patrick's Saltire flying for Northern Ireland at the 2011 Royal Edinburgh Military Tattoo (left to right: The Netherlands, New Zealand, Northern Ireland, Norway)
St Patrick's Saltire flying for Northern Ireland from The Royal Barge Gloriana at the Thames Diamond Jubilee Pageant on 3 June 2012