The Nameless King

The Nameless King is a boss in Dark Souls III.

Lore
The Nameless King was the firstborn son of Gwyn, Lord of Sunlight, the first lord. The Nameless King inherited the sunlight from his father and fought as a dragon-slayer during the Age of Gods. He once wore an ancient ring capable of boosting the strength of miracles. The Nameless King was the God of War, and was said to have respect only for arms and nothing else, and wielded the Sunlight Blade and Great Lightning Spear miracles. The ancient covenant of the Warriors of Sunlight is closely linked to him. In ancient times they were referred to as his warriors, and he was said to watch over the covenant closely. Dragon Slayer Ornstein was the first knight to train under the Nameless King.

At some point, the Nameless King's foolishness led to the loss of the annals, and as punishment, he was stripped of his deific status and expunged from history. All trace of him, including statues, were destroyed. Sunlight Blade, which had the power to boost a weapon with rays of the sun in the form of lightning, was left on Gwyn's coffin, perhaps as a final farewell.

At some point, he sacrificed everything to ally himself with the Ancient Dragons, the very creatures he had once hunted. He fought alongside the Stormdrake in countless battles.

Or, alternatively, The Nameless King allied with the Ancient Dragons, causing Gwyn to remove his son from the annals of history, expunging him, and eliminating all traces of his existence within Lordran.

Warrior of Sunlight
In Dark Souls, the Nameless King shares an iconic symbol with the Warrior of Sunlight covenant, the Sunlight Medal. The covenant itself is closely related to the firstborn, the members being referred to as his warriors, and the god is said to watch over the covenant closely. Assuming the player meets the correct requisites, it is possible to join by praying at the Sunlight Altar, located in the Undead Parish, or by talking to Solaire of Astora, a fanatical member.

Statues
In Dark Souls, a statue of a mother holding a sword-wielding child, thought to represent the Nameless King, is located in front the Sunlight Altar bonfire. This statue also appears in several places, such as above the Firelink Altar and behind the coffin holding the Darkmoon Seance Ring. The sword the child is wielding shares a distinct resemblance to the Sunlight Straight Sword.

There is a missing statue in the cathedral housing Gwynevere, which most likely depicted the adult Nameless King, and was removed when he was expunged from the annals.

Location
Found in Archdragon Peak by ringing the bell located just before the Great Belfry bonfire.

Drops

 * Soul of the Nameless King