Some of the important characters in the story are listed here for the convenience of the readers. Other characters will be introduced in the story.

(NOTE: This list mentions the characters and their titles according to the first chapter of the story.)

King Viserys Targaryen

King of the Andals, the Rhoynar and
the First Men.
Lord of the Seven Kingdoms
And the Protector of the Realm.

💠 Successor of Jaehaerys I
💠 Son of Prince Baelon Targaryen (father) and Princess Alyssa Targaryen (mother)
💠 Elder brother of Prince Daemon Targaryen
💠 Last rider of the dragon Balerion
💠 Wielder of the Valyrian steel sword named 'Blackfyre'

💠 Children:
1) Rhaenyra (from Aemma Arryn)
2) Aegon, Helaena, Aemond and Daeron (from Alicent Hightower)

Queen Alicent Hightower

💠Daughter of Ser Otto Hightower
💠Wife of King Viserys I
💠Mother of Aegon, Helaena, Aemond and Daeron

Princess Rhaenyra Targaryen

💠Daughter of King Viserys I and Queen Aemma Arryn
💠Princess of Dragonstone
💠Heir to the Iron Throne
💠Mother of Jacaerys and Naerys
💠Rider of the dragon Syrax
💠 'The Realm's Delight'

Prince Daemon Targaryen

💠Younger brother of King Viserys I
💠Husband of Lady Laena Velaryon
💠Rider of the dragon Caraxes
💠Wielder of the Valyrian steel sword named 'Dark Sister'
💠 'The Rogue Prince'
💠 'Prince of the City'
💠 'Lord Flea Bottom'

Ser Otto Hightower

💠Father of Queen Alicent Hightower
💠Hand of the King during the last years of King Jaehaerys' reign
💠Former Hand of King Viserys I

Lord Corlys Velaryon

💠Master of Driftmark
💠Lord of the Tides
💠Former Master of Ships
💠Husband of Princess Rhaenys Targaryen
💠Father of Lady Laena and Ser Laenor
💠 'The Sea Snake'

Princess Rhaenys Targaryen

💠Lady of Driftmark
💠Daughter of Prince Aemon Targaryen and Lady Jocelyn Baratheon
💠Wife of Lord Corlys
💠Mother of Lady Laena and Ser Laenor
💠Rider of the dragon Meleys
💠 'The Queen Who Never Was'

(I know that she's supposed to have black hair but HBO decided that it should be otherwise. So, I apologise.)

Lord Lyonel Strong

💠Lord of Harrenhall
💠Hand of the King
💠Father of Ser Harwin and Lord Larys

Ser Harwin Strong

💠Heir to Harrenhall
💠Son of Lord Lyonel Strong
💠Brother of Lord Larys Strong
💠Sworn Protector of Princess Rhaenyra
💠 'Breakbones'
💠 'Brokenbones'

Lord Larys Strong

💠Master of Whispers
💠Lord Confessor
💠Son of Lord Lyonel Strong
💠Younger brother of Ser Harwin Strong
💠 'Clubfoot'

Ser Criston Cole

💠A knight of the Kingsguard
💠Sworn Protector of Queen Alicent

Lady Laena Velaryon

💠Daughter of Lord Corlys Velaryon and Princess Rhaenys Targaryen
💠Wife of Prince Daemon
💠Rider of the dragon Vhagar

Ser Laenor Velaryon

💠Heir to Driftmark
💠Son of Lord Corlys and Princess Rhaenys
💠Husband of Princess Rhaenyra
💠Rider of the dragon Seasmoke