Warcraft II: Tides of Darkness

In the wake of the First War — which brought the Fall of Azeroth at the end of the Orcs' campaign in Warcraft: Orcs & Humans — the survivors of Azeroth flee by sea to the human kingdom of Lordaeron, and the Orcs resolve to conquer it in what becomes the Second War. Both sides gather new allies and powers, including naval and air forces and mightier spellcasters. The Orcs gain the upper hand at first, but the Humans and their allies seize the initiative, helped along by an Orc rebellion stirred up by the warlock Gul'dan, who covets the sunken Tomb of Sargeras. The Alliance eventually drives the Horde back to Blackrock Spire — where their commander, Anduin Lothar, is slain — before, in the final clash at the Dark Portal, exterminating one Orc clan and capturing the Horde's supreme commander and what remains of his forces. To guard against further invasions, the Alliance destroys the Dark Portal.