Gimli, son of Glóin, was a Dwarf of the House of Durin and a member of the Fellowship of the Ring. Unlike other Dwarves, he readily fought alongside Elves in the War of the Ring against Sauron at the end of the Third Age.
After the defeat of Sauron, in the early Fourth Age, he was given the lordship over the Glittering Caves at Helm's Deep, which he presided over until he departed from Middle-earth.
Gimli was the son of Glóin and a nephew of Óin, both former companions of Bilbo Baggins. He was a descendant of Durin the Deathless, father of the first house of the Dwarven people. Gimli was descended from, but was not a member of the royal line. Through his father, Gimli was also the first cousin once removed of Balin, Lord of Moria.
It is stated in Unfinished Tales that Gimli was prevented from traveling with his father on the Quest of Erebor because Thorin and Company thought him too young.