|Although this article is based on canonical information, the actual name of this subject is pure conjecture.
Last Hearth is the seat of House Umber and the northernmost castle before reaching the Wall, thus making it the closest settlement to the Wall. As Jon Snow previously predicted, Last Hearth was the first major obstacle in the path of the White Walkers and their army of the dead since breaching the Wall.
Lord Ned Umber swore allegiance to House Stark after the death of his father, Lord Smalljon Umber, at the Battle of the Bastards. Traditionally a loyal house to House Stark, with Lord Greatjon Umber being a good friend of Lord Eddard Stark and being the first to declare Robb Stark the King in the North during the War of the Five Kings, House Umber joined forces with House Bolton due to Jon Snow using the wildlings in his army; Last Hearth and House Umber were often the first, if not the primary, resistors to wildling raids that the Night's Watch were unable to prevent due to being the northernmost house, hence their hatred of the wildlings.
Prior to the Night King’s attack on Last Hearth, Ned Umber is instructed by the Starks to return to the castle and rally the bannermen sworn to his house.
Sometime after the battle, a group of Free Folk and Brotherhood Without Banners led by Tormund and Lord Beric Dondarrion, makes it to Last Hearth after escaping the fall of the Wall. They find blood but no corpses in the courtyard of the castle. Going deeper into the dark castle, they stumble upon Eddison Tollett and the survivors of the Night's Watch.
The combined group finds Lord Ned Umber dead inside the castle, pinned against the castle walls with a group of severed limbs in a spiral formation around his body. Beric deduces that it is a message sent by the Night King. Tormund notes that, with them at Last Hearth, the the army of the dead is between them and Winterfell, and they will have a difficult time giving chase on foot. Edd says that his own group rode from Castle Black and they can double up on the horses. While Tormund is turned around, the dead Ned Umber reanimates as a wight and slashes at Tormund with a knife, emitting a terrifying screech. Beric quickly burns the wight with his flaming sword, and the entire spiral symbol is lit on fire.
In the books
In the A Song of Ice and Fire novels by George R. R. Martin, no equivalent battle has occurred. The TV show has surpassed the timeline of the books, so it is unclear if an equivalent battle will occur.