The banner of Saint Edward the Confessor (+1066), Saint George's Cross, was the de facto flag of England at least since 1348 (alongside the royal standard).
A Catholic Flag!
"As a very sensible Irishman said in a letter to a Dublin paper: 'The Union Jack is not the national flag of England.' The national flag of England is the Cross of St. George; and that, oddly enough, was splashed from one end of Dublin to the other; it was mostly displayed on shield-shaped banners, and may have been regarded by many as merely religious"
Gilbert Keith Chesterton, Christendom in Dublin (1933), p. 9.
Spanish Cross of Burgundy. This Cross is very interesting since in was the Flag of the Spanish for centuries in the South and West of what is now the United States of America--the Flag of New Spain, and would have been very familiar to the Southerners who later developed the Confederate flag which is very reminiscent thereof. Also the flag of the Carlists.
Saint Patrick Saltire
The above flag has French and Spanish origins and was lately adopted by England for Ireland and incorporated (along with the Scottish white cross, in the present day British flag).
The Union Flag (The Union Jack) 1801
The Confederate flag has a blue cross imposed upon a white cross in the form of an x (like that of Saint Patrick and Saint George). This blue cross is also featured in the flag of Nova Scotia below.
