Ithaka, commonly referred to by its inhabitants as the "Cradle of Snakes", is an Imperial Ocean World and Feral World located in a sector of space known as the Reef Stars in the Segmentum Obscurus. This is a known recruiting world of the Iron Snakes Space Marine Chapter. It is from this tempestuous water world that the Iron Snakes draw most, if not all, of their Neophytes.
Since Imperial records first began to mention the Chapter, the Iron Snakes have taken it upon themselves to be the particular protectors of the Reef Stars, although they undertake this protection in their own, autonomous manner. The inhabited worlds of the Reef, while varied in their level of technological development, each were given some form of advanced communications technology that could be used to summon the Iron Snakes to their world when a dire emergency demanded it. This technology often became highly ritualised into the cultures of the Reef Stars' human colony worlds. The Iron Snakes are little more than a half-remembered myth or legend to some worlds in the sector, but an awe-inspiring reality to others. Regardless of how they are viewed, the Iron Snakes take their duty to the Reef Stars as seriously as only the Astartes can, and will go to any lengths possible to protect the sector and its citizenry.
Despite being designated an Ocean World by the Imperium, Ithaka does possess significant landmass, including tropical islands and viciously cold polar regions. The Iron Snakes are therefore able to train in a series of different environments, although the sea is most precious to them.
Ithaka is a world largely covered in very deep oceans and home to a wide variety of native sea life, including the great serpentine Water Wyrms which play an important role in the Iron Snakes' own distinctive Chapter cult. A kraretyer, or mature male bull Water Wyrm, is known to grow up to 300 metres in length. The Chapter uses these Wyrms in hunting exercises for its Initiates, and in the ritual punishment of Oethanar. The Water Wyrms are known to cause a retyarion (wyrm-storm), which are ferocious squalls that seem to follow the movement of the marine serpents across the planet. A retyarion eventually causes a seunenae ("the folding walls of iron"), which is a giant, kilometres-high tsunami that rises out of the deep waters and comes crashing into the settled islands. The water from Ithaka's oceans is considered sacred by the Iron Snakes, and is carried by the Chapter's Astartes to anoint every planet upon which they step foot. This ritual is called the "Rite of the Giving of Water". When the Iron Snakes return to their homeworld from a mission, what remains of the water they took with them is given back to Ithaka.
Iron Snakes Fortress-Monastery
The Iron Snakes' actual fortress-monastery, which they refer to as the Chapter House, is located on Ithaka's moon, Karybdis, and features a great bell as large as a Space Marine Drop Pod. The Chapter House is a mighty bastion with sloped turrets lined with Earthshaker Cannons, massive curtain walls, and hardpoint blisters of Hydra batteries. The Chapter House contains armouries, forges, training halls, a chapel and an Apothecarion. It also contains a central pool known as the Hall of the Balneary. The Balneary is fifty metres square and filled with sacred sea-water imported from Ithaka, far below. The Tholos lies beneath the Chapter House, anchored deep in the rocky crust of Karybdis. The Tholos is a stockade for the Astartes of the Iron Snakes that was seldom used due to the meticulous discipline of the Chapter. Its most common residents were prisoners of war, held pending interrogation under the watchful eyes of the Veteran Astartes of the Iron Snakes who served as the wardens known as Archons.
- Codex: Space Marines (6th Edition), pg. 31
- Inferno! 29, "Crimson Storm" by Dan Abnett
- Tactica Imperialis: A History of the Later Imperial Crusades by Dan Abnett, pp. 12, 14
- Warhammer Monthly (Comic), "Ophidium"
- Warhammer Monthly (Comic), "Regicide"
- Brothers of the Snake (Novel) by Dan Abnett
- Salvation's Reach (Novel) by Dan Abnett