Cathedral of the Deep

A huge cathedral of the Deep, home to Rosaria and the Deacons, and the gateway to Ariandel.

Suggested level: 30–40

Bosses

Deacons of the Deep: A crowd of deacons around a coffin. Always strike the deacon glowing red to drain the boss bar.

Bonfires

Cathedral of the Deep
Cleansing Chapel
Rosaria's Bed Chamber
Deacons of the Deep

Items found here

Barbed Straight Sword: Dropped by Longfinger Kirk, who invades in the large room past the mimic below the balcony (be embered).
Executioner's Greatsword: At the very end of the Hollow section up the stairs by the Estus Shard obelisk, bearing left.
Astora Greatsword: Near an obelisk, two left turns into the Hollow section up the stairs by the Estus Shard.
Cathedral Knight Greatsword: Random drop from greatsword-wielding Cathedral Knights.
Drang Hammers: Beside the second giant in the flooded cathedral, nearer the Deacons of the Deep bonfire.
Saint Bident: Behind two large doors past the giant in the open flooded area opposite the Deacons arena.
Notched Whip: In the Cleansing Chapel bonfire room.
Heavy Crossbow: Random drop from crossbow-armed Cathedral Knights, such as the one on the cathedral rafters.
Arbalest: On the rooftops above the left elevator from Cleansing Chapel: climb the ladder, drop onto the roof and cross to the second roof.
Saint-tree Bellvine: Drop into the water right of the Estus Shard obelisk and walk past the white Deep enemies; it lies on the ground.
Spider Shield: Dropped by the hostile Brigand NPC met shortly after the first Cathedral of the Deep bonfire.
Spiked Shield: Dropped by Longfinger Kirk, who invades in the large room past the mimic below the balcony (be embered).
Pierce Shield: Sold by Patches for 3,000 souls while Siegward is in the well; Siegward also gives it at the end of his questline.
Crest Shield: Up a winding path to the right after the first set of stairs.
Cathedral Knight Greatshield: Random drop from Cathedral Knights carrying greatshields.
Curse Ward Greatshield: Inside the small tower on the right of the courtyard reached across the bridge past the Hollow section.
Helm of Thorns: Appears in Rosaria's Bed Chamber after you kill the invader Longfinger Kirk.
Cathedral Knight Helm: Random drop from Cathedral Knights (also found near Consumed King's Garden).
Maiden Hood: Behind the giant in the open flooded area of the cathedral, opposite the Deacons arena.
Archdeacon White Crown: Appears beside the Deacons of the Deep bonfire after defeating the boss and resting there.
Drang Armor: Beside the second giant in the flooded cathedral, nearer the Deacons of the Deep bonfire.
Armor of Thorns: Appears in Rosaria's Bed Chamber after you kill the invader Longfinger Kirk.
Cathedral Knight Armor: Random drop from Cathedral Knights (also found near Consumed King's Garden).
Maiden Robe: Behind the giant in the open flooded area of the cathedral, opposite the Deacons arena.
Deacon Robe: Random drop from the robed Deacons around the Cathedral of the Deep.
Archdeacon Holy Garb: Appears beside the Deacons of the Deep bonfire after defeating the boss and resting there.
Drang Gauntlets: Beside the second giant in the flooded cathedral, nearer the Deacons of the Deep bonfire.
Gauntlets of Thorns: Appears in Rosaria's Bed Chamber after you kill the invader Longfinger Kirk.
Cathedral Knight Gauntlets: Random drop from Cathedral Knights (also found near Consumed King's Garden).
Maiden Gloves: Behind the giant in the open flooded area of the cathedral, opposite the Deacons arena.
Drang Shoes: Beside the second giant in the flooded cathedral, nearer the Deacons of the Deep bonfire.
Leggings of Thorns: Appears in Rosaria's Bed Chamber after you kill the invader Longfinger Kirk.
Cathedral Knight Leggings: Random drop from Cathedral Knights (also found near Consumed King's Garden).
Maiden Skirt: Behind the giant in the open flooded area of the cathedral, opposite the Deacons arena.
Deacon Skirt: Random drop from the robed Deacons around the Cathedral of the Deep.
Archdeacon Skirt: Appears beside the Deacons of the Deep bonfire after defeating the boss and resting there.
Poisonbite Ring: Down in the water right of the Estus Shard obelisk, on a narrow path behind a Ravenous Crystal Lizard.
Deep Ring: Dropped by a Deacon up a ladder past the left elevator from Cleansing Chapel.
Lloyd's Sword Ring: Along the balcony with the attacking giant, reached by the right elevator from Cleansing Chapel.
Aldrich's Sapphire: Dropped by the Deep Accursed in a side room far below the mimic room, off the balcony path.
Ring of the Evil Eye+1: NG+ only: tucked behind the big altar that stands before the Deacons of the Deep fog gate.
Ring of Favor+2: NG++: in a roof corner below the ladder past the left elevator from Cleansing Chapel.
Seek Guidance: Cathedral of the Deep: on a corpse in a dim upper room past the first giant, down the stairs to the left.
Rejoice: Buy the Catarina set from Patches and drop it to Siegward stuck in the well outside the Cleansing Chapel.
Prostration: Patches gives it after you forgive him at Firelink, or confront him in the Cathedral of the Deep.
Small Doll: Dropped by the Deacons of the Deep.
Deep Braille Divine Tome: Cathedral of the Deep: dropped by a Mimic below the balcony where the giant attacks.
Paladin's Ashes: Cathedral of the Deep: behind a hostile knight to the left of the first bonfire.
Soul of the Deacons of the Deep: Dropped by the Deacons of the Deep.
Estus Shard: Cathedral of the Deep: just outside the Cleansing Chapel bonfire, by the obelisk with praying enemies.
Undead Bone Shard: Cathedral of the Deep: on a tombstone jutting over a drop, down the stairs near a white tree past the Grave Warden.

Walkthrough: Cathedral of the Deep

Go down left of the Cathedral of the Deep bonfire, beat the sword NPC and take the Paladin's Ashes.
Halfway up the first stairs turn left, follow the path and turn right for a Titanite Shard in an alcove.
At the top of the first stairs go right to the Crest Shield.
Drop onto the axe hollow on the steps and kill him for the Spider Shield.
In the area with dogs and crossbowmen, a Large Soul of an Unknown Traveler lies on a ledge.
Light the Cleansing Chapel bonfire; the Notched Whip sits in a corner.
Just outside, where hollows pray by an obelisk, take an Estus Shard.
Head right and drop into the flooded lower area for the Saint-tree Bellvine on a stump. A held torch keeps leeches away.
Up the steps at the end: a Titanite Shard to the right and a Crystal Lizard ahead with a Twinkling Titanite.
Another Crystal Lizard further on drops a Twinkling Titanite; climb the nearby stone steps for a Titanite Shard.
Drop to the sleeping Ravenous Crystal Lizard and kill it for a Titanite Scale.
A narrow gap between buildings near it leads to the Poisonbite Ring.
Go back outside and up the steps for a Titanite Shard in a window, then drop to the Cleansing Chapel bonfire.
Climb into the graveyard past the obelisk and keep left for the Astora Greatsword.
Head the other way to a T junction, go left and drop for a Fading Soul and the Executioner's Greatsword.
Cross the bridge, beat the Cathedral Grave Warden and go down the arrow-riddled slope for an Undead Bone Shard, Repair Powder x3, two Young White Branch pickups and two Large Soul of an Unknown Traveler pickups.
Climb back toward the tower: a Titanite Shard to its left, the Curse Ward Greatshield inside, and a ladder to kick down.
Left of the main doors, roll through crates for Rusted Coin x2.
Right of the main doors, a body holds a Red Bug Pellet.
Cross the narrow roof and take the Large Soul of an Unknown Traveler at the far end.
Clear the crossbowmen below, ambush the Thralls from the buttress and drop onto Red Bug Pellet x3; Undead Hunter Charm x3 is at the end of the walkway.
Below, turn into a side room for a Soul of a Nameless Soldier (more Thralls wait).
Follow the outer wall to a dead end with an Ember.
Open the double doors into the cathedral and take the Duel Charm by the poison statue on the left.
Through the dining room ride the lift to open a shortcut, ride back up and take the long stairs down for a Deep Gem.
Run around the balcony (the giant can be dealt with first) for a Soul of a Nameless Soldier, Lloyd's Sword Ring and Exploding Bolt x8.
Through the far door, take the first left over a bridge-like walkway for the Seek Guidance miracle.
Back across and up the ladder is an Ember.
Drop to the balcony, go down the stairs and kill the Mimic for the Deep Braille Divine Tome. Save it for Karla to keep Irina on her light path.
Further down, a Deep Accursed drops Aldrich's Sapphire; the room also has an Ember.
Up the steps beyond, Longfinger Kirk invades if you are embered. He drops the Barbed Straight Sword and Spiked Shield.
Kill the giant in the large hall and collect a Soul of a Nameless Soldier and the Maiden Set.
Through the double doors by the giant and down the steps, take the Saint Bident and Homeward Bone x2 outside.
Back inside, wade forward and go up the steps on the left for a Large Soul of an Unknown Traveler.
Kill the second giant at the far end for a Pale Tongue, the Drang Armor Set and the Drang Hammers.
Above the giant's spot, clear the shrine area and grab an Ember overlooking the water.
NG+ only: the Ring of the Evil Eye+1 is behind the shrine.
Facing the shrine, take the door on the left; past the double doors meet "Siegward" and take Duel Charm x3 beside him. This scene does not happen if you already reached the upper rafters.
If he is not there, leave and come back through the blue double doors; a bridge is now up. Talk to him and cross it: it is Patches, who drops you into the hall below.
After the fall, go through the door under Patches' spot and down the stairs to open the last Cleansing Chapel shortcut.
Back through that shortcut, a door on the left leads to a lift and a ladder; the enemy above drops the Deep Ring.
Through the hole beyond, climb the roof and turn right down another roof for the Arbalest; a Pale Tongue lies at the end of the long roof.
NG++ only: the Ring of Favor+2 is at the opposite end of this roof.
Come back inside on the rafters and go right for a Blessed Gem.
Work across the rafters, kill the crossbow knight and drop twice to find Patches. Tell him you know who he is for the Prostration gesture and a Rusted Coin.
Patches now sells the Catarina Set. Buying it means he can no longer rescue Greirat later.
Climb the stairs and clear the room; the passive one drops the Red Sign Soapstone. Light the Rosaria's Bed Chamber bonfire.
Talk to Rosaria, Mother of Rebirth to join Rosaria's Fingers. Do not offer Pale Tongues yet if you want Sirris' quest.
If you killed Longfinger Kirk, the Armor of Thorns Set is close by.
If Patches never showed up here, he springs his trap in the Bell Tower behind Firelink instead; grab the Fire Keeper Soul and drop down onto the coffins to escape.
Climb the tower again, drop onto the shrine roof and slip through the windows for the rafters' Estus Shard if you missed it.
Trade a Homeward Bone with Pickle-Pee, Pump-a-Rum Crow for the Call Over gesture and Iron Bracelets if not done yet.
The Fire Keeper Soul lets the Fire Keeper cure Dark Sigils. Do not cure them if you are following Yoel and Yuria.
Reload Firelink; Patches now sits upstairs. Refuse his apology for the Prostration gesture and a Rusted Gold Coin. Reload again for the Patches Squat gesture.
If his shop still lacks Catarina Set, find Siegward stuck in the well by the Cleansing Chapel and talk to him, then buy the set.
Throw the armor down the well to Siegward for the Rejoice gesture.
Turn right at the giant shrine. Embered, you can summon Anri of Astora and Horace the Hushed behind the shrine and Sirris by the fog.
Defeat the Deacons of the Deep for the Small Doll and the Soul of the Deacons of the Deep.
Rest at the new bonfire and take the Archdeacon Set near the altar.