Marcel's Army is an army of vampires created by Marcel Gerard in New Orleans. They compose all of the vampires present in New Orleans during Marcel's reign and, later, during his joint reign of the city with Klaus. However, after Klaus discovered Marcel's treachery back in 1919, Elijah banished Marcel from the city and revoked the privileges of all vampires in New Orleans.
For the following month, the remaining vampires waged war against the New Orleans witches until their new leader, Diego, agreed to negotiate a ceasefire. A peace treaty brokered by Elijah led to a new status for the vampires and peace between the factions. However the vampires have resumed their loyalty to Marcel, who was planning to reclaim the city by himself. After the collapse of the peace treaty, Marcel launched an all out assault against the Originals to reclaim the French Quarter and his rule of the city but the surprise reveal of the werewolves in the Correa family ruined his plans and his vampires were all killed either by the Guerreras or by a resurrected Mikael.
After the Guerrera werewolves took over the French Quarter and banished the vampires to Algiers, Marcel started to rebuild his army with several turned humans from all over New Orleans, such as Gia. In addition, Marcel has recruited his former rival, Elijah Mikaelson, as his co-leader, to help him train his new vampires as well as maintain their position in the city by securing the support of an Original vampire.