Gimli, son of Glóin, doesn't get much time in the spotlight in The Lord of the Rings films. Although his antics with Legolas are fondly remembered as a highlight of the trilogy, Gimli's history is mostly ignored. There's only one real moment in The Fellowship of the Ring that touches upon Gimli's past: when he enters the Mines of Moria in hopes of seeing his cousin, Balin, who was once Lord of Moria.
Source：https://www.cbr.com/lord-rings-gimli-balin-connection-with-moria-explained/
