These military ensigns were to be replaced by flags that bore the images of saints.

(For example, Saint Stephen would go to war "under the banners of St George and St Martin".) Later the red and silver striped flag (occasionally complemented with the colours of the ruling dynasty) became habitual.

Although from the 15th century onward the red-silver-green twist occurred more and more frequently on the silk strings of document seals and sometimes on the pily fringes of military banners, the present order of the three colours was only described in 1806, and it was only Act XXI of 1848 that officially provided for the first time that the colours "red, white and green" be used.

Source: National and historical symbols of Hungary