Wikipedia
Ultra-royalist
The Ultra-royalists (, also called as Ultras) were a French political group active from 1815 to 1830 under the Bourbon Restoration. The Legitimists, another of the main right-wing families identified in René Rémond's classic opus Les Droites en France, were disparagingly classified with the Ultras after the 1830 July Revolution by the victors, the Orleanists, who deposed the Bourbon dynasty for the more liberal king Louis-Philippe.
Ultraroyalist also refers to "someone who is a very strong supporter of royalism."