During the 9th Century, a falling star crashed to earth as a young squire and knight aspirant, Gareth, happened upon it. From within the fallen star, a dragon emerged; as this happened, a group of Picts led by the sorcerer Brude attacked, trying to enslave the dragon and capture the nine eggs he guarded. Though Gareth's intervention allowed the dragon to win, Gareth was wounded and the dragon, seeing him as worthy for saving one of the eggs, shared his heart with the young man, which in turn gave the dragon speech. However, Brude uses a slavery spell called the Sorcerer's Curse on the dragon, christened as Drago by Gareth – rendering him powerless in daylight or by the light of a flame and meaning that Drago will be under Brude's control by the full moon – before claiming the dragon eggs.
When they next meet, Drago explains his purpose to raise the young dragons he has brought as friends to mankind. However, he also states that he needs help to retrieve the eggs as he cannot do it himself due to the curse. With aid from Gareth, the female Celtic warrior Rhonu, a priest named Lorne and others who oppose Brude, Drago sets out to rescue the eggs. Gareth's first attempt at rescuing the eggs fails, with him getting captured by the clan. Brude originally intends to kill him, but stops upon learning about Gareth's connection with Drago. With help from Rhonu and Lorne, he successfully escapes with the eggs.
Gareth then convinces the group to head towards Hadrian's wall, with Rhonu telling her uncle Traevor to gather the clans who oppose Brude. Travelling with Rhonu and Lorne, the trio are forced to go on foot after one of the eggs is accidentally destroyed. Along their journey, Drago tries to teach Gareth how to shadow-jump (an ability gained from the curse Brude inflicted), although he apparently fails. However, while trying to free a group of people captured by the painted clan, Gareth shows an act of valour – temporarily freeing Drago from the curse. The trio escape from Brude and the clan after Gareth sacrifices one of the dragon eggs and then shadow-jumps to safety.
Before the group reaches the wall, Gareth confesses to Drago that he isn't a knight and that the Southern side of the wall is a cruel place with no respect for the Old Code of King Arthur – although Drago still sees Gareth as a friend and forgives him. Upon reaching the gate, Gareth, Lorne and Rhonu are arrested and the dragon eggs seized upon learning of the Painted clan heading towards the wall. At the full moon, Drago (now fully under Brude's control) and the Painted tribe attack, although Gareth and Rhonu escape with help from Lorne's magic. As Gareth interrupts the sale of the dragon eggs and battles the corrupt knight Sir Horsa to protect them, his act of valour frees Drago – who aids both the soldiers and the northern clans led by Traevor. Gareth slays Sir Horsa, while Rhonu battles and kills Brude – although she is fatally wounded herself. With Brude dead and Drago free, the remainder of the Painted tribe retreats.
Following the battle, Gareth tends to Rhonu – who is saved as one of the unhatched dragons shares its heart with her. Gareth becomes a knight and leader of the settlement, with peace achieved between the North and South as Hadrian's Wall is renamed the Dragon's Gate. Gareth and Rhonu finally express their love for each other as the baby dragon that saved Rhonu begins to hatch.
For the following decades, peace reigns and Gareth and Rhonu become king and queen, ruling with honor and justice. They and Drago together raise the seven remaining dragons including Draco, and the Scarred One alongside their son Walter. However, Walter is unintentionally neglected as time goes on by Gareth, and the death of Queen Rhonu, his mother (caused by her dragon dying in a storm), causes Walter to hate dragons and denounce his birthright. Soon after, Walter has two twin children, Mehgan and Edric, who are born with scales on their face and back respectively as a result of their heritage of being dragon-hearted, a fact Walter mistakenly calls a curse.
Years later, Drago realizes this when he fails to die when Gareth does and finds that he is bonded to Edric, now a Sheriff, though not entirely, and realizes both the boy and his sister share his powers; Edric has Drago's strength, and the Viking-aligned Mehgan can manipulate fire. The battling twins come to a head when Mehgan steal Drago's heartfire; the source of his power and fiery breath, and then takes the throne for her own. She then banishes her brother and Drago escapes to rescue him.
Drago then kidnaps both siblings when they next fight, and forces them to reconcile; Edric had sent Mehgan away for supposedly killing their father when in truth it was he who was responsible for the terrible accident, and Mehgan, desperate to see her brother live a normal life, took the blame. Realizing their strength comes from working together, the twins reconcile and set out to retake the heartfire from Thorgrim, Mehgan's treacherous lover, who believes the heartfire is a gift from the god Odin and want to use it for conquest.
In the resulting battle, Thorgrim consumes the heartfire and it burns him alive, allowing Edric to kill him. Mehgan is mortally wounded and, knowing they will survive by sharing their hearts, Drago gives up the heartfire so that they may live and rule together as equals. Drago then dies in peace, and joins his kin in the stars of the constellation Draco, his great deed accomplished.
In the years and perhaps even centuries after, dragons continued to multiply, abetting mankind until one of the original seven surviving hatchlings Drago brought to earth named Griffin betrayed the dragons and killed humans, wanting to dominate the world. Fearing that all dragons were akin to Griffin, the Chinese emperor ordered the killing of every dragon in the country. In Britain, as kingdoms rose and fell and possibly simultaneously with Griffin's fall from grace, some, such as the tyrannical king Freyne, also began killing the dragons. When Freyne was killed by peasants in a rebellion and his son Einon was mortally wounded, Einon's mother, Queen Aislinn and the knight Sir Bowen, have him taken before a dragon whom the widowed queen implores to save the boy's life. The dragon replaces Einon's wounded heart with half of its own on the promise that Einon will rule with justice and virtue. However, Einon soon becomes more tyrannical than his father, enslaving the former rebels and forcing them to rebuild a Roman castle. Bowen believes that the dragon's heart has twisted Einon, and swears vengeance on all dragons.
Twelve years later, the grown Einon has his castle rebuilt. Kara, the peasant who wounded Einon, asks the king for pardoning her father after years of slavery, but Einon instead kills him in order to "free" him. As for Bowen, he has become a very skilled dragonslayer. Brother Gilbert, a monk and aspiring poet, observes Bowen slaying a dragon, the Scarred One, and follows him to record his exploits. Bowen stalks another dragon to its cave, but the confrontation ends in a stalemate. The dragon states that he is the last of his kind, and thus if Bowen kills him, he will be out of a job. The two form a partnership to defraud local villagers with staged dragonslayings. Bowen then calls the dragon Draco, after the constellation. Unknown to Bowen, Draco is the very dragon who shared his heart with Einon, and through this connection, any pain inflicted upon one is also felt by the other.
Disgusted by what her son has become, Aislinn helps Kara escape. Kara tries to rally the villagers against Einon's tyranny, however they instead offer her as a sacrifice to Draco, who takes her to his lair where he and Bowen inadvertently reveal their friendship to her. Einon arrives to recapture her and fights Bowen, declaring that he never believed in the Old Code and only told Bowen what he wanted to hear so he would teach him how to fight. Draco intervenes and Einon flees. Kara asks Bowen to help overthrow Einon, however the disillusioned knight refuses.
Bowen and Draco's next staged dragonslaying goes poorly and their con is exposed. Draco then takes Bowen, Kara, and Gilbert to Avalon, where they take shelter among the tombs of the Knights of the Round Table and King Arthur. Draco reveals the connection between himself and Einon, stating that he hoped giving the prince a piece of his heart would change Einon's nature and reunite the races of Man and Dragon. Through this action Draco hoped to earn a place in the stars, where dragons who prove their worth go after they die. He fears that his failure will cost him his soul, and agrees to help Kara and Gilbert against Einon. After experiencing a vision of King Arthur that reminds him of his knightly code, Bowen agrees to help as well.
With Bowen and Draco on their side, the villagers are organized into a formidable fighting force. Aislinn presents Einon with a group of dragonslayers, secretly knowing that killing Draco will cause Einon to die as well. The villagers are on the verge of victory against Einon's cavalry when Gilbert strikes Einon in the heart with an arrow. Draco falls from the sky and is then captured. Einon realizes that he is effectively immortal as long as Draco remains alive, and determines to keep the dragon imprisoned. Aislinn attempts to kill Draco during the night, but Einon stops and kills her instead.
The rebels invade Einon's castle to rescue Draco as Bowen battles Einon. Draco begs Bowen to kill him as it is the only way to end Einon's reign, but Bowen can't bring himself to kill the dragon who has become his best friend. Einon charges at Bowen with a dagger, but Bowen reluctantly throws an axe into Draco's exposed half-heart. Einon and Draco both die, and Draco's body dissipates as his soul becomes a new star in the constellation. Bowen and Kara then go on to lead the kingdom into an era of justice and brotherhood.
However, despite Draco supposedly being the last dragon, Bowen finds one last dragon; Draco and the Scarred One's son as an egg, which he entrusts to Brother Gilbert for safekeeping. The friars at the monastery pledge to hide the dragon away, with Friar Peter protecting him and teaching him for 20 years. The task of taking care of the dragon is passed to a young and gullible friar named Mansel. An orphaned stable boy named Geoff, who dreams of one day becoming a knight like Bowen, also lives at the monastery, doing menial chores; he tricks Mansel into manual labor and discovers the hidden dragon, named Drake by the monks. At first Geoff is afraid, but realizes Drake is more afraid of him. They soon form a close friendship, just as Bowen and Draco once did.
Meanwhile, two Chinese citizens, appearing to be a frail old man and his son, enter the kingdom and ask Friar Peter if he knows anything about dragons, as there is a prophecy stating that "a dragon's heart will doom mankind when a two-tailed comet blazes across the night sky". They also explain that the comet will come in a matter of days, so they want to make sure that there are either no dragons around, or, if there is one, confirm that its heart is pure and that it will not be tempted into fulfilling the prophecy. Meanwhile, the current King makes a mysterious man named Osric his adviser, and Osric pledges to unite the kingdom under the old code, but corrupts it by forcing each status of citizen to wear a certain color of tunic.
With these terrible new laws and Geoff complaining of the current plight, he and Drake are surprised by some bullies, and Drake is forced to take his first flight. During this, the two Chinese travelers learn of Drake's existence and start to train him to use his dragon abilities, including fire-breathing, flight, using his tail, claws, and teeth, and to exhale ice breath, the last of which is a rare skill that few dragons manage to master. Before this time of teaching, Geoff discovers that the Chinese grandson is the princess of China in disguise, who reveals the dragon Griffin's role in trying to overthrow mankind and that Drake is, due to this and the subsequent slayings of all other dragons in China, truly the very last of his kind.
The Chinese citizens are captured and Geoff is made a knight for his friendship with Drake. Osric takes them to battle a group of rebels where a fight engages, during which Osric fakes a fatal blow and asks Drake to give him half his heart. Realizing that the attempt is a trick, Geoff rallies Drake in an escape. Drake later masters his fire-breathing skills for the first time. At the castle, Osric then recognizes a familiar box; Master Kwan, the elder Chinese, recognizes Osric's true identity and orders the amulet burned. Osric recovers the box and discovers his lost heart. Out of revenge for her ancestor's slaying of the dragons, Osric throws a knife at Master Kwan's companion, the girl Lian, but Kwan intervenes and dies.
Geoff and Drake arrive, and as the comet comes into view, Osric reveals himself as Griffin, whose heart was cut out by the emperor. Lian had carried his heart with her to protect it. When he recovers possession of his heart, he resumes his true dragon form and asks Drake to join him in the conquest of mankind. Recalling how Griffin would have cost him his soul if Geoff had not intervened, Drake refuses and challenges Griffin in battle. After a short but fierce dragon fight, Drake uses his ice breath to freeze Griffin to death and shatters him to pieces. Geoff is injured by a piece of ice lodged in his heart in the melee; so Drake offers a piece of his own, securing his place in the constellation Draco. The old code is restored and Lian returns to her royal duties for a time. Mansel is awarded guardianship of Brother Gilbert's scrolls and has a life of prayer and devotion. Geoff and Drake go on to become brothers, having discovered the familial bond that is all they ever truly wanted. With this, man and dragon were reunited again and peace returned once more.
Below is a list of the known dragons from the Dragonheart films.
- Drago- first of his kind to land on earth along with nine eggs, seven of which survived, and bonded first to a knight named Gareth, who would later become king. Later bonded to Gareth's grandchildren: Mehgan and Edric. Died sacrificing his life to ensure Edric and Mehgan lived.
- Rhonu's Dragon- First of the seven eggs Drago guarded to hatch. Bonded with Gareth's wife, Queen Rhonu. Was killed by a lightning storm, which also killed Rhonu.
- Draco- The dragon who bonded with King Einon and later helped Sir Bowen defeat him at the cost of his own life. Was one of the original seven hatchlings Gareth and Drago raised together. Father of Drake. Mate of the Scarred One.
- The Scarred One- Draco's mate and Drake's mother. Killed by Bowen. Was one of the original seven hatchlings Gareth and Drago raised together.
- Griffin- One of the original seven hatchlings Gareth and Drago raised together. Turned evil and tried to destroy mankind. Trapped in human form by the emperor of China and had his heart stolen. Regained it and was killed by Drake shortly after. Was the only known evil dragon and was responsible for the extinction of most of his race through fear of him.
- Drake- Draco and the Scarred One's son. The last living dragon, bonded to Sir Geoff. Killed Griffin.