An orphan growing up on the streets of Flea Bottom in King's Landing, "Dunk" was chasing a pig one day when he was seen by a Hedge Knight. The Knight, Ser Arlan of Pennytree, had fought for King Daeron II in the Blackfyre Rebellion. During the final battle of that conflict his squire, Roger of Pennytree, was killed by a knight with three castles on his shield.
Following the death of his squire, who had been his sister's son, Ser Arlan traveled to Kings Landing where he spotted Dunk in Flea Bottom, and offered to take him on to be his squire. Deciding that being a squire was a better option than being a thief, Dunk accepted Ser Arlan's offer, traveling the Seven Kingdoms with him for the next dozen or so years.
Ser Arlan was a good and honorable man who took his vows as a knight seriously. Dunk noted that although some Hedge Knights turned highwayman during lean times, "The Old Man" never did. Traveling to a tourney being held at Ashford Meadows when Dunk was about Sixteen or so (Dunk didn't know exactly how old he was), Ser Arlan caught a fever that killed him three days later. His last act was to knight his squire. Ser Dunk buried his old master on the west side of a hill, so that Ser Arlan could watch the sunsets.
Ser Dunk decided to go on to the Tourney, hoping to become a champion, "if only for an hour." Stopping for supper at an inn, Ser Dunk met a drunken lordling who was terrified of him; and a skinny, bald stable boy. Although the boy asked to accompany him to the tourney, Ser Dunk told him he was better off at the inn.
The stable boy followed Ser Dunk to the tourney and set about squiring for him. The boy asked for his name, found "Dunk" to be a hilarious name for a knight and asked if it was short for Duncan. Wondering if it might be, and knowing that the most notable thing about him was his height (he was measured at one inch less than seven feet), Ser Dunk of Flea Bottom became Ser Duncan the Tall. His newly acquired squire gave his own name as Egg.
What Ser Duncan learned later was that the drunken lordling was Egg's elder brother, Prince Daeron Targaryen, and that Egg was Prince Aegon, fourth son of King Daeron II's fourth son, Prince Maekar of Summerhall. Prince Maekar's eldest brother, Prince Baelor, Hand of the King, Prince Baelor's heir, Prince Valarr, and Egg's second brother Prince Aerion were also present for the festivities celebrating the thirteenth nameday of Lord Ashford's daughter.
Prince Aerion, destined to become known as Aerion the Monstrous, attacked some puppeteers, breaking the fingers of Tanselle Too Tall, a young Dornish woman. Ser Duncan's defense of the puppeteers resulted in a Trial of Seven which left Prince Baelor dead, killed during the fight by his brother Prince Maekar. Humbled by the death of his brother and the conduct of his two eldest sons, Maekar agreed to Egg's request that he be allowed to continue squiring for Ser Duncan, and they set off for Dorne.
In the years that followed, they traveled through Dorne (failing to find the puppeteers), fought pirates, visited Egg's brother Aemon at the Citadel in Old Town, took service for a time with Ser Eustace Osgrey, and freed Lady Webber from the unwanted attentions of a determined suitor. They also helped prevent a second Blackfyre Rebellion at a tourney held to celebrate the marriage of Lord Ambrose Butterwell to a daughter of House Frey. It was here that Ser Duncan was formally introduced to Bloodraven, a reputed sorcerer and a bastard son of King Aegon the Fourth.
Lord Commander Edit
Some twenty years later, Egg became King Aegon V (more commonly known as Aegon the Unlikely). Ser Duncan was again Aegon's Sworn Shield, as a Knight of the Kingsguard. Ultimately, he was raised to Lord Commander, the finest and most famous knight in the land.
Although Ser Duncan had never approved of his squire's desire to hatch a dragon's egg, he was present at Summerhall when his King attempted to do so. The result was a disasterous fire that came to be remembered as the Tragedy of Summerhall. Despite Ser Duncan's skill and great strength, he died, unable to save his king or his namesake, Duncan Prince of Dragonflies. King Aegon's granddaughter, Princess Rhaella, gave birth to a son, Prince Rhaegar, at some point during the disaster.