Its Lance Ritter brigade, dubbed the "Wall of Leonster", is where most of the Manster District's strength comes from, and it is thanks to it that the Manster District has resisted Thracia's consecutive invasions. However, after the Yied Massacre, half of Leonster's lance knight brigade is decimated, Prince Quan and his wife Ethlyn are killed, and the Gáe Bolg is lost, so Thracia is able to successfully conquer the Manster District following the Battle of River Thracia, and perhaps as a symbolic measure, Thracia burns Leonster Castle.
Soon afterward, the Kingdom of Grannvale (soon to be the Grannvale Empire) invades the Manster District, and forces the conquering Thracians into a peace treaty, in which Grannvale annexes the Manster District, including Leonster Castle, and the country is renamed the Northern Kingdom of Thracia, with Duke Bloom of Freege installed as its King.
Prince Leif eventually manages to free Leonster Castle from the grip of the empire, but King Bloom, who is in Alster Castle, resists Leif's attempts to oust him, and most of Leif's fighting force is decimated, thus Leif has to hold out in Leonster Castle until Seliph's army is able to attack Alster Castle.
After Seliph's army defeats the Grannvale Empire, Leonster is made the capital of the New Kingdom of Thracia, under the new King Leif.
Notable citizens of LeonsterEdit
- Calf - King of Leonster during Sigurd's tale, husband of Alfiona, father of Quan
- Alfiona - Queen of Leonster during Sigurd's tale, wife of Calf, mother of Quan
- Quan - Prince of Leonster, husband of Ethlyn, father of Altena and Leif
- Ethlyn - The wife of Quan, Sigurd's sister, mother of Altena and Leif
- Altena - Princess of Leonster and Thracia (technically), daughter of Quan and Ethlyn, sister of Leif, raised by Travant after he killed her parents
- Leif - Prince of Leonster, son of Quan and Ethlyn, brother of Altena
- Finn - Knight of Leonster, serves both Quan and Leif, in Thracia 776, he is implied to be Raquesis's lover and Nanna's father
- Nanna - Princess of Nordion, daughter of Raquesis and in Thracia 776 also the daughter of Finn, Leif's love interest
- Carrion - Knight of Leonster, his father died in battle, Hannibal rescued him and his mother
- Selfina - Knight of Leonster, daughter of Dorias, married to Glade
- Kain - Knight of Leonster, his parents both died in battle serving Leonster
- Alva - Knight of Leonster, Kain's best friend
- Robert - Knight of Leonster, an orphan who admires Selfina
- Glade - Knight of Leonster, Selphina's husband, Finn's best friend
- Xavier - Former general of Leonster, allied with Freege in order to protect the people
- Dorias - Duke of Leonster, lost his right arm during a battle in Alster, an advisor to Leif
Leonster is a corruption of Leinster, the Irish province.