Tanith is briefly visited in Ghostmaker, and described by the Ghosts in various novels. It was a heavily forested world located in the Sabbat Worlds, a cluster of planets in the Segmentum Pacificus. The main export of Tanith was nalwood, which becomes extremely rare after the planet's destruction. Nalwood trees were capable of uprooting and moving; entire forests migrating and making paths through the forests useless as the constant movement erased them. As a result of this, the Tanith have a strong sense of direction, bred into them by adapting to this environment. It is assumed that Tanith had one major sea or ocean and polar ice caps. Although Tanith's oceans are never mentioned, Trooper Lesp is said to have come from a coastal settlement called Tanith Longshore, where he worked in the fishing industry; confirming that there was at least one sea on Tanith's surface. The capital city of Tanith - surrounded by a giant wall, presumably to keep the nalwood trees from moving into the city - was Tanith Magna. The world was governed by an Elector, and the main governmental building appears to be the Assembly (although Rawne mentions a place called the Elector's Palace when under the influence of psykers on Monthax). It is unclear as to whether or not the Elector was elected as the title sounds, or if it was an inherited position like a king. Tanith was split up into counties, not unlike Ireland (Counties Pryze and Cuhulic are mentioned). Each city on Tanith had a Militia, from which a number of Ghosts (including Corbec, Larkin, Mkvenner and Rawne) are drafted into the Imperial Guard. Tanith's native wildlife included larisel, small animals hunted by woodsmen - for their fur and possibly for food - and shoggy; small amphibian creatures with bulging eyes that dwelled by woodland pools in Tanith's forests.
The Tanith people are always described as pale-skinned and dark-haired, with a lilting, sing-song accent. Most Tanith men (and youths) are tattooed with blue ink. No female Tanith are mentioned in detail, and it is presumed that none made it off-world, but if any did they did not accompany the Tanith First. The main Tanith curse-word is feth, which is used in the same context as "fuck", but it is also the name of an ancient Tanith tree-god. Sacra is an alcoholic beverage favored by the Tanith, although it is not clear if it is native to Tanith. Many Tanith names begin with "Mk", a variant of "Mc" or "Mac" used by the Irish and Scottish, from whom inspiration for the Tanith appears to have been drawn. There are also elements of Welsh in their language. Tanith pipes are described as a small clutch of spidery reeds attached to a bellows bag which is squeezed rhythmically under the arm, and make a sound similar to Uilleann pipes. Their initial use on Tanith was to guide off-worlders through the shifting forests, but in the Tanith First they are used to rally the men and spook the enemy (although they have a similar effect on the Tanith's allies). According to Scout Trooper Bonin, most old Tanith families (his own included) baptize and officially name their children at the age of eight, as naming children at birth was considered premature and a child would grow into the names he or she would need. Bonin also remarks that this tradition wasn't observed much in Tanith's final years. Tanith was home to the legendary Nalsheen wood warriors, a brotherhood of Tanith who used the martial art cwlwhl (pronounced kil-wil); using blade-tipped staffs to fight off multiple foes. The Nalsheen were responsible for overthrowing the corrupt Huhlhuch Dynasty and ushering in the free modern era of Tanith. Mkvenner is the only remaining Tanith to have been trained in cwlwhl, but has reluctantly admitted that he never completed his training. The Nalsheen used proto-Gothic - the early form of both High and Low Gothic used presently in the Imperium - as their private language.
Following the death of Warmaster Slaydo, a splinter fleet of Chaos slipped past the picket set up by the Imperial Navy thanks to the newly-appointed Warmaster Macaroth's change of tactics. This small fleet attacked and conquered six worlds, one of which was Tanith. The Chaos armada bombarded Tanith from orbit, and deployed ground troops to kill whatever the shelling missed. The forests of Tanith burned under the crippling firepower of the fleet. It is not clear if Tanith had any functioning planetary defence artillery batteries, but it is likely that the Tanith Militia fought back against the invaders. Colonel-Commissar Ibram Gaunt was one of the last people to leave the planet before its demise, and was saved by a youth called Brin Milo, whom he took with him in gratitude. Milo confirms that he was the only civilian to leave Tanith alive, being too young to join the Guard.
It is possible that some Tanith survived the loss of their homeworld simply because they were not on the planet when it came under attack. A Tanith longshoreman featured briefly in Titanicus (also by Abnett), and drunkenly accused the Orestes PDF of being "fething amateurs". He was promptly attacked and presumably killed by the husband of a woman serving in the Orestes PDF.
In Blood Pact, a small chapel was erected in memory of Tanith on Balhaut. It is not described in great detail, but it contains a large holographic projection of Tanith.
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