When the dragons of the Age of Ancients were defeated, the winners of the war, calling themselves gods, founded and constructed a prosperous land: Lordran. Anor Londo, as Lordran's capital city, became legendary with the passage of time; an unreachable city of the gods. It was built by Lord Gwyn at the dawn of the Age of Fire, and served as his throne, surrounded by other gods, his brave knights, and his army of Silver Knights.
In the Age of Fire, when the First Flame started to exhibit signs that it was fading, and after unsuccessful attempts to prevent this, Lord Gwyn descended to the Kiln with the already charred Black Knights in a dramatic last attempt. He sacrificed himself, offering his own soul in order to extend the Age of Fire, and he succeeded, thus prolonging the Flame. Sadly, for the gods, this selfless sacrifice originated other problems: the Undead Curse was created when Gwyn linked the fire, breaking the natural course of the world and soon, most of Anor Londo's inhabitants abandoned the city and Lordran.
Heroes and pilgrims from many eras have tried to reach the city. To reach Anor Londo, they must surpass Sen's Fortress and defeat the gatekeeper, the Iron Golem. Countless have perished in their attempts, but many have also been successful and have reached the city of the gods, such as: the Darkmoon Knightess, Black Iron Tarkus and Solaire of Astora. It's also important to note that prevalining in the Battle of Stoicism grants access to Anor Londo.
The Chosen Undead is tasked by the primordial serpent Kingseeker Frampt to retrieve the Lordvessel from Gwynevere, Princess of Sunlight. In the now-deserted Anor Londo, only one god remains in the city: Dark Sun Gwyndolin, last-born of Gwyn. In order to deceive the Chosen Undead, he creates an illusion of his sister and the sun, making Anor Londo appear bathed in sunlight and glory, as it once may have been. But should this veil of deception be liften, one shall learn the truth, that Anor Londo is wrapped in darkness. The real Gwynevere has long since left the city with her future husband, Flann, God of Flame.
The Darkmoon Blades now seek vengeance for crimes against the gods and operate under Gwyndolin's command. Also, as her name suggests, Darkmoon Knightess, the Firekeeper of Anor Londo, is a member of this covenant. Under Anor Londo's cathedral, only accessible by using a mechanical turning staircase, is a circle of statues made in rememberance of Gwyn and the knights who descended with him to the Kiln. Behind his statue, there is a secret, honorary tomb made for him, from where Dark Sun Gwyndolin governs the Blades of the Darkmoon Blades.
The forsaken capital still preserves a couple of interesting points:
The grand cathedral of the city was originally Gwyn's castle, and is still guarded by Silver knights, Bat Wing Demons and giant Sentinels. In the cathedral itself, Dragonslayer Ornstein and Executioner Smough form the last line of defense before the illusion of Princess Gwynevere. The Giant Blacksmith, a friend of Hawkeye Gough, resides in the left wing of the cathedral.
Aside from the grand cathedral is a smaller, but still ornate building that hosts a statue of Gwynevere and an incredibly large painting made by Ariamis, protected by the Painting Guardians. This painting - only if a particular object is used on it - grants passage to the Painted World of Ariamis.