The Battle of Dagorlad occurred in the year 3434 of the Second Age. It was fought between the army of the Last Alliance under Gil-galad and Elendil and an army of orcs and other creatures loyal to Sauron. The battle took place on the great, treeless, open plain between the Dead Marshes and Cirith Gorgor. The army of the Last Alliance won the battle and was able to attack the Morannon, the entrance to Sauron's land of Mordor. Later, in the Third Age, the Dagorlad was the site of many battles between Gondor and various Easterling armies.
The word Dagorlad means "Battle Plain" in the Sindarin language