Much of this is shown in The Lord of the Rings, especially at the end of Return of the King. Aragorn is crowned King of Gondor and reunited with Arwen. They get married and later have a son.

Peter Jackson's The Lord of the Rings: The Two Towers introduced the kingdom of Rohan and its inhabitants. The Rohirrim were once the Gondorians' closest allies, but in the film, their ...