The Dominion of Agustria (アグストリア諸公連合, Agusutoria Shokō Rengo lit. Alliance of the Various Lords of Agustria) is a western country in Jugdral located west of the kingdom of Grannvale and north of the kingdom of Verdane. Hoðr, the Black Knight, was one of the founding lords of Agustria and his descendants run the country. It is Jugdral's largest country in area. Seliph, who is of Grannvalean heritage, was born in northern Agustria.
In Chapter 1, despite King Imuka's desire for peace, Elliot, heir to the house of Heirhein, decides to lead a troop of soldiers to aid Verdane and attack Grannvale's border. Eldigan of Agustria's house of Nordion intervenes on Grannvale's half and chases away Elliot after he fails to listen to his words.
In Chapter 2, King Chagall is bewitched by Manfroy into killing his father, and imprisons Eldigan and puts Lachesis in danger, which ultimately leads to Sigurd and his army having to take over most of Agustria except Madino Castle and Silvail Castle, and this conflict reaches a temporary end with an agreement stating that Sigurd will not try to capture the of the northern part of Agustria, while King Chagall will wait a year before he will regain control of the country. This agreement breaks down after six months, and after King Chagall tries to dislodge Sigurd and his army from the country, Sigurd is again forced into action.
After Sigurd captures Madino Castle, King Chagall forces Eldigan to fight Sigurd. Either Eldigan is defeated and killed, or Lachesis talks to him and gets him to try to ask for a truce with King Chagall, but this results in Eldigan's death. After this, King Chagall is killed, and Silvail Castle is captured. The Orgahill Pirates decide to invade Agustria, but they are stopped by Sigurd and his army.
Sigurd is branded a traitor, and Grannvale annexes Agustria under the leadership of the Frieges. It stays this way for over 17 years, and even after the holy war ends, Agustria is still in a state of civil war. However, with Ares's arrival and effort, the civil war ends, and he becomes King of Agustria (with the help of his cousin Diarmuid - if he does not inherit lands from his father's side - and Nanna - if either she is single or she is Ares's lover).
Characters from Agustria
House of Nordion (in southern Agustria)
- Eldigan - The ruler of Nordion who wields the Demon Sword in knightly devotion to any master.
- Grahnye - Lady of Nordion Castle by marriage, mother of Ares.
- Lachesis - The Lady of House Nordion who adores her older brother to the point that other men pale in comparison.
- Ares - The son of Eldigan and Grahnye and heir to Mystletainn that joined up with a mercenary captain after his parents passed away. Becomes the king of Agustria after the end of the holy war.
- Diarmuid - Son of Lachesis, raised in Isaach.
- Nanna - The charismatic daughter of Lachesis who has her mother's graceful bearing.
- Chagall - The foolish prince and later king of Agustria during the first generation.
- Imuka - The beloved and wise king of Agustria before his death by his son, Chagall.
- Elliot - Son of the lord of Heirhein Castle in southern Agustria.
- Boldor - Lord of Heirhein Castle.
- Macbeth - Lord of Anphony Castle in southern Agustria.
- Clement - Lord of Mackily Castle in southern Agustria.
- Jacobi - A mercenary hired by Chagall.
- Seliph - Son of Sigurd and Deirdre, of Grannvalean heritage born in Agusti in northern Agustria.
- Eve - Loyal Cross Knight of House Nordion and father of Tristan and Jeanne.
- Eva - Loyal Cross Knight of House Nordion.
- Alva - Loyal Cross Knight of House Nordion.
- Tristan - Son of Eve, raised in Isaach.
- Jeanne - Daughter of Eve, raised in Leonster in the republic of Manster.