The Great Houses are the most powerful of the noble houses of the Seven Kingdoms. They exercise immense authority and power over their vassals and territories and are answerable only to the Lord of the Seven Kingdoms, King of the Andals and the First Men.
Before the Targaryen Conquest, each of the Seven Kingdoms was ruled independently by a powerful royal family. During the Conquest these families were either destroyed and replaced, or defeated and forced to swear allegiance to King Aegon, reigning from the Iron Throne in King's Landing.
The Gardeners, Hoares, and Durrandons were slain and replaced by the Tyrells, Greyjoys, and Baratheons respectively, while the Lannisters, Rylens, Arryns, and Starks surrendered peacefully and were allowed to remain in control of their lands. In addition, Aegon raised up the Tullys to rule over the Riverlands, which had been under ironborn occupation prior to his arrival. After a long civil war in the Borderlands and the Stormlands, King Aenys I, Aegon's son and heir, elevated House Blackgard to a Great House, as well. Only House Martell of Dorne resisted his armies, but was later brought into the fold through a peaceful marriage-alliance some two centuries later.
Each Great House has a large number of vassal houses serving it, most of whom in turn have smaller vassals under them, extending all the way down to farmers and landed knights. Each Great House rules over its territory and is responsible for collecting taxes and, in times of war, raising troops to fight for the king. Otherwise they are largely left to operate autonomously to simplify the bureaucracy and governance of the realm.
Robert's Rebellion ended in the exile of the last Targaryens, with House Baratheon replacing them on the Iron Throne. In exchange for their services in aiding the rebellion, House Rylen was granted independence from the Seven Kingdoms and once again became the royal house of the Tiger Islands.
The War of the Five Kings has seen changes amongst the Great Houses. House Baratheon, including both of its rival branches House Baratheon of King's Landing and House Baratheon of Dragonstone, has become extinct. The Riverlands and the titles of House Tully, defeated in the war and exiled, have been given to its former vassal House Frey, though the other Tully vassals remain in open rebellion against the Freys. With the coronation of Queen Cersei I Lannister, the Crownlands are now held by House Lannister, the de facto royal house. Although defeated early in the war and stripped of lands and titles, House Stark has regained control of the North with its victory against its former vassal House Bolton. After Ellaria Sand's coup in Dorne wiped out the last of the legitimate Martell line, House Baerley was elevated as the new sovereign Great House of Dorne. With the extinction of House Baratheon, House Harrigon of Smithestone ascended as the new ruling Great House of the Stormlands diplomatically through a Stormmoot. After Lord Tybalt Lannister's failed attempt to rebel against Cersei Lannister's rule and his subsequent death during the Day of Daggers, House Montrose was elevated to the new Great House of the Westerlands via a royal edict. Following the Massacre at Ebonheart, Steffon Blackgard killed Eddin Blackgard and elevated House Blackgard to a Royal House when declared the Borderlands a sovereign state, with himself as the self-styled Black King of Ebonheart.
The Great Houses
Current Great Houses
- House Arryn - rulers of the Vale of Arryn from the castle of the Eyrie. Currently in rebellion against the Iron Throne (integrated with the Kingdom of the North).
- House Blackgard - rulers of the Borderlands from the castle of Ebonheart of Blackgard. Currently in rebellion against the Iron Throne.
- House Greyjoy - rulers of the Iron Islands from the castle of Pyke. Currently in rebellion against the Iron Throne.
- House Rylen - independent royal house of the Tiger Islands from the castle of The Claw. Currently at war with the Iron Throne and its allies.
- House Lannister - the de facto royal house of the Seven Kingdoms from the Red Keep of King's Landing in the Crownlands. Formerly were also the Great House of the Westerlands.
- House Montrose - rulers of the Westerlands from the castle of Casterly Rock. Named the new Great House of the Westerlands by royal decree following the Day of Daggers.
- House Stark - rulers of the North from the castle of Winterfell. Currently in rebellion against the Iron Throne.
- House Harrigon - rulers of the Stormlands from the castle of Smithestone. Ascended to the position through a Stormmoot.
- House Baerley - rulers of Dorne from the castle of Sunspear. Usurped their position through a coup d'état orchestrated by Ellaria Sand.
- House Targaryen - claimant royal house of the Seven Kingdoms, former royal house and rulers of the Crownlands from the castle of the Red Keep. Currently based out of Dragonstone and fighting against House Lannister for control of the Seven Kingdoms.
- House Tarly - rulers of the Reach from the castle of Horn Hill after House Tyrell is defeated in the Sack of Highgarden.
Former Great Houses
- House Tully - the former rulers of the Riverlands, ruling from Riverrun, until the Red Wedding. Currently prisoners of House Frey.
- House Smithe - rulers of the Smithlands from the castle of Hornworth. Betrayed and forced into exile by House Harrigon during the Massacre at Hornworth. Afterwards, the Smithlands were absorbed into the Stormlands by House Durrandon.
- House Bolton - former vassals to House Stark, rulers of the North from the castle of Winterfell after usurping their positions from House Stark during the Red Wedding. Ramsay Bolton, the sole heir, was killed in the aftermath of the Battle of the Bastards by his own hounds. With his death, Randar Bolton (Roose's older brother) has become the de facto Lord of the Dreadfort and head of House Bolton, returning House Bolton to their former status as vassals.
Extinct Great Houses
Only seven Great Houses have ever gone fully extinct, three of which were as a result of their defeat in the Targaryen Conquest, four of which as a result of the War of the Five Kings:
- House Casterly - rulers of the Westerlands until they were swayed away from their home by the legendary trickster Lann the Clever.
- House Durrandon - rulers of the Stormlands. Asterion the Black, the founder of House Blackgard, was a distant cousin of Durran Godsgrief, thus House Blackgard descends from the male line of the House. Orys Baratheon, founder of House Baratheon, married the daughter of the last king of House Durrandon, thus House Baratheon descends from the Durrandons through the female line.
- House Gardener - rulers of the Reach. House Tyrell claims descent from House Gardener through the female line, and House Florent is actually a cadet branch of House Gardener, with a better claim to rule based on lineage than the Tyrells. Several other Houses from the Reach also descend from House Gardener.
- House Hoare - rulers of the Iron Islands and (through conquest) the Riverlands. After their defeat, Aegon Targaryen commanded the ironborn to select a new family from among their number to rule over the rest, under the Targaryens. They selected House Greyjoy.
- House Baratheon - rulers of the Crownlands and Stormlands from the Red Keep and Storm's End respectively. Extinct in actuality due to all mainline members being deceased but the bloodline is still alive, technically speaking, through Robert Baratheon's many bastard children. The line legally ended with the death of Tommen Baratheon, the bastard son of twins Cersei Lannister and Jaime Lannister, who received the Baratheon name through his mother's cunning.
- House Baratheon of Dragonstone - rulers of the Stormlands from the castle of Dragonstone, claiming the Iron Throne. Extinct as of the Battle of Winterfell.
- House Baratheon of King's Landing - rulers of the Crownlands from the castle of the Red Keep in King's Landing, and the former royal house. Extinct as of King Tommen's suicide following the destruction of the Sept of Baelor.
- House Martell - rulers of Dorne from the castle of Sunspear. Wiped out by the Sand Snakes in their coup d'état, though due to the Sand Snakes all being bastard children to Oberyn Martell, the bloodline is technically still alive.
- House Frey - former vassals to House Tully, rulers of the Riverlands from the castle of Riverrun after usurping their positions after the Red Wedding. Walder Frey and all of his sons were murdered by Arya Stark after the Battle of the Bastards, leaving its lordship uncertain.
- House Tyrell - former rulers of the Reach from the castle of Highgarden. The bloodline is scattered after the Destruction of the Great Sept of Baelor and the Sack of Highgarden.
Heads of Great Houses in the TV series
Heads of Great Houses at the beginning of the TV series
Heads of Great Houses after the Red Wedding
House Bolton and House Frey were elevated to Great House status after the betrayal at the Red Wedding, which they switched from the Stark side to the Lannister side in the war. The Lannisters rewarded them by naming the Boltons as the new rulers of the North (displacing the Starks) and the Freys as the new rulers of the Riverlands (displacing the Tullys).
Edmure Tully was already the functional leader of House Tully for several years prior to the start of the narrative due to his father's old age and failing health, and became the official head of House Tully upon his father's death at the beginning of Season 3.
House Stark was scattered after the Red Wedding with survivors fleeing into exile or assumed dead, and thus was left with no clear leader as a faction after the Red Wedding.
Current heads of Great Houses in the TV series
Of the eleven characters who were the heads of Great Houses at the beginning of the TV series, by the end of Season 6 only one remains alive: Tandis Rylen
More broadly, Sweetrobin Arryn, Edmure Tully, and Walder Frey might be included in this count: Sweetrobin's father Jon Arryn died right before the first episode, though his rule is only nominal given that he is underaged, intellectually stunted, and a succession of regents have actually "led" House Arryn on his behalf. Edmure, meanwhile, was the acting head of House Tully for several years prior to the beginning of the TV series due to his father Hoster's health declining to the point that he was bedridden: Edmure became the official head of House Tully upon his father's death, but was later captured by Frey/Lannister forces. Walder Frey has remained the head of his own family since the beginning of the narrative, but the Freys were only promoted to Great House status after the Red Wedding. For that matter, Olenna Tyrell was always the de facto leader of House Tyrell.
With the deaths of both Mace Tyrell and Walder Frey in the Season 6 finale, only one of the Great Houses is still led by their original ruler at the beginning of the TV series. Even compared to the middle of Season 1, the only ones still alive are those who didn't actually hold the title but functionally ruled (Olenna and Edmure) or who technically held the title but didn't actually rule (Sweetrobin).
After Cersei Lannister learned that her cousin, Lord Tybalt Lannister, had declared himself Lord of Casterly Rock and planned to rebel against her rule, she arranged for the Day of Daggers to take place to eliminate Tybalt and his loyalists. Following this, she issued a royal edict naming House Montrose as the new Great House of the Westerlands, as there was no reason for House Lannister to remain the Great House of the Westerlands now that it was the Royal House.
With the passing of Trevyr Blackgard his thirdborn son and heir, Eddin, has become the new head of House Blackgard, but following Eddin's death at the hands of his nephew, Steffon Blackgard, Steffon is now the new head of House Blackgard and is the self-styled Black King of Ebonheart.