After Mandalore the Indomitable lost a duel of honor to the Sith Lord Ulic Qel- Droma, the Crusaders were drafted into the Great Sith War. But not all of them were exactly satisfied with being led by a non-Mandalorian, and when the war came to an end roughly 4,000 years before Star Wars: A New Hope, with the Mandalorians routed at the planet Onderon, a new faction of Crusaders, calling themselves the Neo-Crusaders, arose, crowning a new Mandalore to strike back against the Republic and Jedi.
Unlike the Crusaders before them, Neo-Crusader armor was highly standardized, to give a cohesive look to the various species that would be adopted into Mandalorian culture beyond the original tribal factions. Gone were the organic accoutrements, leaving a sleek shaped to the plated armor. The Neo-Crusader armor was also color-coded, allowing Mandalorians to denote rank: gold for Field Marshals, silver for front line veterans, scarlet for Rally Masters (a mid-commander rank), and blue for all other Neo-Crusader ranks.
