The Tailtean Plains are a location in the Holy Kingdom of Faerghus.
The Tailtean Plains, outside the capital of Fhirdiad, are a location of both economic and historical importance to the Holy Kingdom of Faerghus. Like Gronder Field in the Adrestian Empire and the County of Gloucester in the Leicester Alliance, the Tailtean Plains are a vital agricultural site. They were also used as the battleground in the Battle of Tailtean in Imperial Year 91, a pivotal confrontation late in the War of Heroes in which the King of Liberation Nemesis was slain by Saint Seiros, breaking the back of the Adrestian Empire's opposition in Fódlan. This was also the spot of a decisive battle where Loog defeated the Emperor to end the War of the Eagle and Lion in Imperial Year 751.
In Imperial Year 1185, the Tailtean Plains again become a battlefield.
Dimitri and Rhea decide to intercept the Adrestian Empire at Tailtean Plains, as they feel that it is the only tactically sound choice to stop the rapid advance of the Empire following their absorption of the Leicester Alliance. Dimitri organizes his men into defensive position, knowing that they will be able to rout the Empire's forces if the Knights of Seiros can arrive on time.
The Empire, led by the Black Eagle Strike Force, arrive as expected and begin battering their way through the Kingdom's defences, which also included several soldiers who willingly converted themselves into Demonic Beasts. Rhea and her Knights eventually arrive, although slower than expected due to poor weather. By the time they arrive, the Empire has already killed most of Dimitri's soldiers, and he himself falls in battle. Following his death, Rhea uses the remnants of the Kingdom's army to cover the Knights of Seiros' retreat as they make their way to Fhirdiad.