By the 15th century, the mythology of the coat of arms would trace its origin back to the Battle of Las Navas de Tolosa in 1212 involving Sancho VII of Navarre, where the cavalry broke the chains of the caliph's slave-warriors and captured an emerald, among other prizes.

A few months later, Francisco Franco signed a decree (BOE of 14 November) that handed to the province of Navarre the Laureate Cross of San Fernando in recognition of their help in the War.

The Diputación was quick to adapt the coat of arms model to the new element and, as in previous cases, the agreement included a picture.

After the Francoist regime, the Laureate Cross of San Fernando was removed, causing great controversy between supporters and opponents of withdrawal.

In 1985, Domingo Aznar Magaña performed a design adaptation of the coat of arms, for use in formal events, ornamentals and the flag of Navarre.