'House of the Dragon' Hightower Family Tree: All About Alicent's House

George R. R. Martin is known for his meticulously detailed worlds, which are like this partly thanks to the long family histories he has penned for his characters.

House of the Dragon, HBO's new prequel series to Game of Thrones, features many important families within Martin's fantasy franchise, one of which is the Hightower house.

The show is set during the Targaryen dynasty's rule over the Seven Kingdoms, and it begins in the reign of King Viserys I (Paddy Considine) and follows as he chooses his daughter Rhaenyra (Milly Alcock, later Emma D'Arcy) to be his heir.

This decision later leads to the Dance of the Dragons, a civil war that broke out between the dragon-wielding house and almost destroyed it. This, in part, is due to one particular character: Alicent Hightower (Emily Carey, later Olivia Cooke).

Here is everything you need to know about Alicent's house.

'House of the Dragon' Hightower Family Tree: All About Alicent's House

House of the Dragon
L-R: Olivia Cooke as Alicent Hightower, Rhys Ifans as Otto Hightower, Milly Alcock as young Rhaenyra Targaryen and Emily Carey as young Alicent in "House of the Dragon." Ollie Upton/HBO

Alicent is the daughter of Otto Hightower, the Hand of the King to Viserys I who previously had the role when his grandfather King Jaehaerys I was on the throne.

The character is important because of not only her close friendship with Rhaenyra but also how intimate she becomes with King Viserys I, who chooses her to be his second wife following the death of Queen Aemma Arryn (Sian Brooke).

Through her marriage to King Viserys I, Alicent has four children: Aegon, Helaena, Aemond and Daeron. And although Rhaenyra is her husband's chosen heir, Alicent soon becomes determined to advance her children's own right to the Iron Throne.

Alicent is not the first Hightower to have close ties with the Targaryen rulers, as the house has a long history with them all the way back to their first leader, Aegon the Conqueror.

Prior to King Aegon I's reign, the Hightower's were rulers in their own right, and the house was founded during the Dawn Age by King Uthor of the High Tower.

The Hightowers ruled over Oldtown and helped build the Citadel, the home of the maesters who are the scholars, healers, messengers, and scientists in the world of Martin's books.

The house came to also gain power over Highgarden through marriage before Aegon's conquest, the location is one Game of Thrones fans will recognize as the ancestral seat of the Tyrell family.

Upon Aegon's conquest of Westeros, the Hightower family chose not to fight against the dragon lords but instead swore fealty to them, and Aegon the Conqueror allowed Lord Manfred Hightower to remain lord of Oldtown.

His great-granddaughter Ceryse Hightower became the first wife of King Maegor I Targaryen. Known as Maegor the Cruel, the ruler had six wives during his reign and no children by Ceryse.

Several Hightowers were lords of Oldtown during the Targaryen reign. During the rule of King Jaehaerys I, the Lord of Hightower was Hobert (Steffan Rhodri) and he is the older brother of Otto, Alicent's father.

Is the Hightower Family in 'Game of Thrones'?

Hightower House does play an important part in the events of Game of Thrones, which is set almost 200 years after the events of House of the Dragon.

The descendants of the Hightower family continued, even after the end of the Targaryen reign, to remain close to the throne. So much so that a Hightower descendant actually becomes queen: Margaery Tyrell (Natalie Dormer).

Margaery Tyrell is the daughter of Alerie Hightower and Mace Tyrell, she wed King Joffrey Baratheon (Jack Gleeson) and, following his death at their wedding feast, later marries his brother King Tommen Baratheon (Dean Charles-Chapman).

House of the Dragon airs Sundays at 9 p.m. ET on HBO and HBO Max.