The Leiston Fortress (レイストン要塞 Reisuton Yōsai) is Liberl Kingdom's national military headquarters of its army in the Trails in the Sky trilogy. It is located on the shore of Lake Valleria in the Zeiss Region, under Maximillian Cid's supervision as base commander.
Said to be widely impenetrable, Leiston's reputation stands till present since the Hundred Days War when it was the only piece of Liberlian territory aside from Grancel that didn't fell into Erebonian occupation. Within those walls, Professor Russell secretly developed the military patrol ships that would later become the key for Liberl's large scale counterattack. The completed ships were dispatched under General Morgan's command directed under Cassius Bright's tactics to cut off the Imperial Army's supply routes and rendering them into smaller divisions. After the war, the stronghold is hailed as an impregnable fortress for its major contribution. It also serves as an asylum for most prisoners to the kingdom.
In Trails in the Sky, Leiston was occupied by Colonel Alan Richard and his intelligence division's coup due to their tightening grip on the Royal Army. With he and his family threatened, Major Cid was forced to relinquish command of the base to the Colonel and helplessly watch helplessly a kidnapped Professor Russell imprisoned in the fortress' research wing.
Fortunately at nightfall, Estelle and Joshua, accompanied by Agate and Tita infiltrate the fortress to comprehend the situation. They reached their way into the research wing discovering Professor Russell's kidnapper and also the mastermind behind most of the events so far. The group eventually frees the Professor and escapes with Major Cid's secret assistance.
After Richard's coup is thwarted, the army starts reorganizing under Cassius's command following his reinstatement to the army. who spends most of his time operating from Leiston. Major Cid, for his loyalty during the coup, is promoted to lieutenant colonel.
- The following events occurred in the first Sky installment.
- Major Maximillian Cid was promoted to lieutenant colonel for his unwavering loyalty during the coup.
- In the prison cells were the following captives: