Who is Benn Gunn from Treasure Island and what is their importance?

Jim discovers Ben Gunn on Treasure Island, where he has been marooned for three years. After three years of solitaire, Gunn has become a bit eccentric, but he has, nonetheless, survived to tell his story. Ben Gunn is instrumental in saving Hawkins and the rest of the crew of the Hispaniola. He shares store of food, as well as the crude rowboat he fashioned on the island..... the boat that Jim used to save the Hispaniola. In the end, Gunn returned to England with the ship.