Since the book proposed a couple of new ideas, I'm including a quick summary of the relevant information. this might be useful for dialogue, general worldbuilding, etc.
- The book was commissioned by the "Ecumenical Authority": a part of the Imperial administration concerned with regulating cults and preventing sectarian conflict.
- Mention of another book: Axiom Catacombs: and Inquiry into the Nature of the Law-Bones by Brago Antipharos. This should be a rather esoteric text dealing with the Earthbones.
- Colovians always bury their dead: common people in graveyards, the wealthy in modern crypts. Colovian tombs are not commonly in use, except by old Colo-Nordic nobility.
- Nibenese originally let the moths eat their dead, or send them down the river in little boats. Both practices are no longer very prevalent, and modern Nibenese either go for burial or cremation. The nobility buries its dead in tombs following Nordic example.
- Mention of the Rain-Coronach, an old religious text involving Kynareth.
- Mention of the Church-Mother Testaments, another religious text (already mostly written).
- Alessia has been buried in a tomb, either beneath the Temple of the One in the Imperial City, or in Sancre Tor (nobody knows exactly).
- Most Emperors have been buried in lavish tombs.
- There is a fashion for boat-shaped coffins in the Nibenay.
- Rich families sometimes sail their dead on a skiff around the Imperial City, before burying them.
- Mention of the Shoni-Etta, a very old text involving the life of Reman. Parts of it have been posted by MK elsewhere. I'm not linking to it, as it is NSFW and also creepy weird.
Funerary Rites of Cyrodiil: Tombs of the West
Machil Coridale, by order of the Ecumenical Authority, Temple District, Imperial City
The people of Colovia know two common methods of interment: burial in the earth, and burial in stone tombs in the Nordic fashion. Both are of a particular fascination to the student of obsequies, as they are intimately bound to the history of Colovia, its peoples, and their peculiar social stratification.
Inhumation in a "common" grave in the earth may seem like a mundane tradition to the layman, given that it is practiced by almost any civilized culture in Tamriel for the obvious reasons of practicality and inherent allegorical quality [for those who have an interest in this matter, I recommend Brago Antipharos' "Axiom Catacombs: and Inquiry into the Nature of the Law-Bones"]. Still, this practice did not come easy to the nascent Nedic civilization, for whom river-burial or consumption through moths were once the preferred means to dispose of their dead.
The first religious codices of the Eight, such as the Rain-Coronach or the Church-Mother Testaments, reflected Nedic prejudices in that they discouraged earth burial. The growing schism between Nibenay and Colovia prevented this dogma from taking hold in the west, as did practical concerns (that is, the absence of a suitable riverways in the Highlands). After the separation from the Marukhati east, Colovians were free to decide their own rites - these being largely defined by their Nordic ruling class.
Nordic tomb-building held a peculiar fascination to the early Nedes, which somewhat belies the supposed religious dominance of the early Alessian church. Of course, the Niben/Colovian split has been greatly exaggerated by past scholars, and there is reason to believe that early Imperial society in the Nibenay was much more Nordic than has until now been assumed. Especially the offices of high nobility, for which native Nedes knew no equivalent, were in large part inspired by Nordic examples - which included tomb building.
The greatest precedent, of course, was Alessia herself, who was entombed in the earth following her death - this to signify her becoming one with the land, assuming its aspect as the Mother Cyrod. This set a precedent for Nedic nobility to build tombs and crypts, and this is the reason why most Emperors have let themselves be buried, some exceptions notwithstanding.
The Nibenese, ever cosmopolitan in their outlook, devised many a clever way around their own doctrines: the fashion for boat-shaped coffins in the east, for example, or the tradition of old and affluent families to take the dead on a boat trip around the Imperial City before entombing them (doubling as one last pilgrimage, even). Even the scriptures show some leniency in this matter: it is written that: "Those who bury their bones in the earth are held for but an hour's breadth, for in all things Mara's grasp will slip, and they too will follow the Waters." Indeed, one of the more notorious Imperial codices, the Shoni-Etta, claims that exactly this happened to Alessia's spirit following the ascendancy of Reman I. Such is the flexibility of Nibenese myth.