Three Hunters
The Three Hunters was the name taken by Aragorn, Legolas, and Gimli during the War of the Ring, when the three companions of the broken Fellowship pursued a band of Orcs across the plains of Rohan to rescue their captured friends.
Background
At the falls of Rauros the Fellowship of the Ring was scattered. Frodo and Samwise set off alone toward Mordor; Boromir was slain defending the hobbits Meriadoc and Peregrin, who were then seized by Orcs of Saruman and of Mordor. Aragorn, Legolas the Elf, and Gimli the Dwarf, finding Boromir dying and the hobbits taken, resolved to follow the captives rather than pursue the Ring-bearer.
The pursuit
Naming themselves the Three Hunters, the trio ran for days across the open grasslands of Rohan, covering great distances on foot in dogged pursuit of the Orc-band. Their chase brought them into the realm of the Rohirrim, where they met Éomer and the Riders of the Mark, who had themselves destroyed the Orcs in a night battle near the eaves of Fangorn Forest. The hobbits, unknown to all, had escaped into the forest during that fight.
Reunion
At the edge of Fangorn the Three Hunters met Gandalf returned as the White Rider, whom they had believed lost in Moria. Together they rode to Edoras and roused King Théoden, and the three companions fought through the remaining battles of the war, at Helm's Deep and in the campaigns of the South. The fellowship of Legolas and Gimli, an Elf and a Dwarf, that began in these days became one of the famous friendships of the age, healing an ancient enmity between their peoples.