The Mon Calamari monarchy served as the government for the planet of Mon Cala. After a lengthy conflict between the Mon Calamari and the [Quarren](/article/quarren], the monarchy, along with a governing council featuring representatives from both species known as the Calamari Council, established a stable and peaceful accord.
During the time of the Clone Wars, Yos Kolina, the 82nd King of Mon Cala, was assassinated, leading the Quarren to refuse support for the crowning of his son, Prince Lee-Char. Under the influence of Separatist ambassador and commander Riff Tamson, the Quarren separated themselves from the Galactic Republic, triggering a civil war. Ultimately, the Quarren switched sides and rejoined the Republic upon discovering the Separatists' plan to replace Chieftain Nossor Ri with Tamson as the ruler of Mon Cala, resulting in the defeat of the Separatist forces and the killing of Tamson. Following the battle's conclusion, Lee-Char was crowned to become the 83rd King of Mon Cala.
Following the transformation of the Republic into the Galactic Empire, Lee-Char declined to accept the Empire's conditions, asserting that it would lead Mon Cala to its downfall. In an attempt to find a peaceful resolution, Moff Wilhuff Tarkin arrived at Mon Cala aboard the Sovereign and dispatched Ambassador Telvar to engage in negotiations with Lee-Char. Despite Telvar's diplomatic approach, Lee-Char remained firm in his stance, prompting Telvar to return to Tarkin for additional instructions. Simultaneously, Darth Vader was also sent to Mon Cala, accompanied by three members of the Inquisitorius and a unit of elite stormtroopers, with the mission of suppressing a Jedi uprising on the planet. They were greeted by Gial Ackbar, the King's Chief of Security, who requested their departure, emphasizing that the Empire had no justification for being there. When they explained their presence was to neutralize a threat to the Empire, Ackbar promptly dismissed the idea, reiterating the need for them to leave. It was at this moment that Telvar's shuttle exploded shortly after its departure. Upon receiving news of the situation, Tarkin made the decision to deploy Imperial forces to conquer Mon Cala.
At some point, Mon Cala was subjugated and the king was abducted and imprisoned.
During the course of the Galactic Civil War, Admiral Gial Ackbar, Princess Leia Organa and her team, traveled to Mon Cala with the objective of convincing Dors Urtya, the regent of Mon Cala, to initiate a rebellion against the Empire. Their objective was to incorporate the might of the Mon Cala Mercantile Fleet into the Rebel Alliance and modify them for combat purposes. Nevertheless, Urtya turned down their plea, expressing concerns for the safety of his people and his king. Subsequently, Organa chose to reach out to Queen Trios, the rebel spy, for assistance in the rescue of the king.
During the war between the First Order and the Resistance, General Leia Organa, along with her Resistance operatives, embarked on a mission to Mon Cala with the intention of enlisting the Mon Calamari people to support the Resistance cause. Initially, King Ech-Char hesitated to join the cause, but he ultimately decided to participate after Chadkol Gee betrayed them to the First Order.