how to get the famous head and similiar artifacts?
are there any other stacking artifacts exept books?
There are many ways to get artifacts in the game, so let me outline them.
1. A counciller finds a rumour of an artifact. If its common, its just a tongue, head, ect. of a saint or other person. Rare is a mid-level artifact, and extraudinary is a super awesome artifact, lvl 5. These artifacts correspond to your religion - norse people can't find the staff of david, etc.
2. Heremetics can create magnum opi, books that boost stats, as well as inventions such as a handgun due to special events. There is also an event where they can find the emerald tablet. Finally, they can gather ingredients, which count as artifacts I guess but aren't very valuable
3. You can smith artifacts - as a count to king you can smith lvl 1 to lvl 2, with a chance of upgrading it to the next level with a payment of gold. As an emperor, you can get a lvl 3 artifact and even upgrade it to lvl 4 under said event. You can smith crown jewels, weapons, and armor, all corresponding to your culture/religion/government (not sure which, could be more than one)
4. If you have jade dragon, then you can obtain artifacts from China, either by visiting to kowtow, Chinese people visiting you, or spending grace to get a lvl 1-3 artifact
5. Also with jade dragon, you can compose your own book, based on your stats, which will take forever to write but will provide some pretty cool bonuses
6. If you have WoL and study the weird, you can get a necromenomicon
7. Random events can give you artifacts, such as the cursed artifacts in India or paintings
8. With Holy Fury, some new artifacts are placed in the game, as reward for reforming a religion or an empire.
9. With Holy Fury and Old Gods, you can raid a saint's burial place and run away with his bones and stuff
10. With Reapers Due, you can get prosthetics - these break upon inheritance
11. you can raid other people for their artifacts using Old Gods, and you can increase your chance obtaining them by being part of a warrior lodge. This is one of the few ways to obtain rare artifacts such as the iron crown of lombardy
12. If a character dies within your court, their artifacts go to you. Basically inheritance only works for landed characters, so if you see a peasant carrying around the holy grail, better catch them fast and take their artifacts. However, unequipped artifacts have a chance of being lost on succession.
Edit: as part of their warrior lodge, africans can also make fetishes