The city of Minas Tirith was besieged following the fall of Osgiliath and the Rammas Echor, Gondor's final barriers against the forces of Mordor. In the retreat to the city, Faramir, son of Denethor, Steward of Gondor, was severely wounded. Since the despairing Steward refused to leave his son's side, the Wizard Gandalf took command of the city's defences. Meanwhile, the enemy forces assembled before the city on the Pelennor Fields. A Great Darkness of smoke and cloud from Mordor blotted out the sun. The Nazgûl or Ringwraiths, Sauron's most feared servants, flew over the battlefield on fell beasts, causing the defenders' morale to waver.