Based partially on the historical figure of the same name, King James I is the ruler of England, Scotland (as James VI), and Ireland, his wife, and consort is Queen Anne. He is a tall man with a brown beard and a fancy crown and clothing. He also has an unknown named dog.
In the first film, he is merely mentioned, with his likeness appearing in a painting brought by the settlers.
In the second film, his character is fleshed out. In stark contrast to his historical counterpart, James is portrayed as a well-meaning, but narrow-minded ruler, which allows him easily led astray more than once by his close friend Governor Ratcliffe, no matter how ridiculous or unlikely Ratcliffe's claims are. He also seems to have primitive views on the Native Americans, as he initially believes them to be mere savages as Ratcliffe did, and is very easily manipulated by Ratcliffe into orchestrating events that lead him to lock Pocahontas away and declare war on the Powhatan people. By the end of the film, however, he is shown the error of his ways and finally places Ratcliffe under arrest for his crimes.
King James didn't appear in the first film but was mentioned by Ratcliffe in the film. Ratcliffe wishes to find gold and bringing it back to England. According to Ratcliffe, this will allow him to become successful and famous, and so gain the favor of the king. Ratcliffe later claims the New World and its riches in King James' name and has the settlement named Jamestown in the King's honor. During the song "Mine, Mine, Mine" Ratcliffe reveals that when he returns with the gold, he believes King James will reward Ratcliffe by Lording him. During the song, Wiggins brings Ratcliffe a portrait of King James, which Ratcliffe sticks his head through the picture, tearing it, while proclaiming his plan to make certain all the gold remains his.
King James made his first appearance in the sequel. After returning to England, Governor Ratcliffe is brought before the King to answer for his crimes in Jamestown (for shooting one of his own men, nearly starting an unnecessary war, almost needlessly costing many lives, etc.). Ratcliffe lies and frames John Smith (the man he shot and a key figure in his downfall and disgrace) for his crimes. King James, largely out of his friendship with Ratcliffe, believes him, and orders Smith to be arrested for treason, with the caveat that he is to be taken alive (most likely so that he could question Smith and get his side of the story). He also sends John Rolfe to Jamestown, with the intention of bringing back the Indian Chief. The meeting will determine whether King James declares war on the Native Americans.
Later, Ratcliffe appears before the King, announcing that John Smith had died in an accident while being apprehended, despite Ratcliffe's attempts to save him. Unknown to the King, this is a lie, as Ratcliffe had purposefully pushed Smith off a roof into a canal (most likely to prevent Smith from possibly unraveling his lies). Ratcliffe attempts to convince King James to immediately war with the Native Americans. Queen Anne insists that they must wait for Rolfe and the Indian Chief. King James, after taking into consideration his wife's and Ratcliffe's words, compromises: Ratcliffe may prepare the Armada, but they will wait for Rolfe and the Chief.
Rolfe later returns with the Chief's daughter, Pocahontas. He insists that the king should meet her, as she is both civilized and intelligent. On the advice of Ratcliffe, King James orders Rolfe to bring Pocahontas to an upcoming ball. If Pocahontas makes a good impression, the armada will not sail. At the ball, King James is initially impressed by Pocahontas, but when Pocahontas calls him a savage for torturing a bear during a bear-baiting (after King James accused her of the same thing for defending the bear), he orders her and her bodyguard Uttamatomakkin imprisoned for treason. According to rumor, King James intends to have Pocahontas beheaded the next dawn.
Later, King James and Queen Anne are preparing to have court, when Pocahontas, Uttamatomakkin, John Rolfe, and a disguised John Smith burst into the room. The King attempts to have Pocahontas arrested, but Uttamatomakkin disables the guards and Queen Anne urges her husband to listen to the girl. Pocahontas tells the King that there is no gold at Jamestown, and thus, no reason to fight. She is corroborated by John Smith, who chooses to reveal himself, thus unraveling Ratcliffe's treachery.
The King, realizing how foolish he was to believe Ratcliffe's lies, orders Pocahontas, John Smith, and John Rolfe to stop Ratcliffe. After being defeated, Ratcliffe is confronted by King James and his guards. Ratcliffe attempts to lie again, but this time, King James refuses to believe him and has his guards arrest him for his treachery and lies. King James then dispenses rewards for Pocahontas, Smith, and Rolfe. To Pocahontas, he grants peace to her people. John Smith is given his own ship to sail the world with, and John Rolfe is offered a promotion to Lord Advisor to the Royal Court. Rolfe turns down his reward, instead choosing to return to Virginia, as he has fallen in love with Pocahontas.