This beautiful object in the Munich Residenz is often called "a ciborium or portable altar," but this is somewhat misleading! The entire structure, which resembles a kind of tent or canopy, is a ciborium. Ciboriums typically covered the main altar in a medieval church. 1/4 https://twitter.com/ArthurWestwell/status/1177226571867987969

Ciboriums were sometimes built into the church architecture itself (especially later on), but the one in the Munich Residenz is free-standing. Like its fellows, it covers an altar; but this is where the name confusion happens. The Residenz ciborium contains a portable altar! 2/4

The green porphyry slab, encased in wood and silver with enamel panels, is actually removable. It can be taken out of the ciborium setting entirely! I've found textual sources that describe this practice, as it was common to process an altar around inside a church. 3/4

I'm looking forward to sharing more on the practice of removal and addition in regards to medieval devotional objects. The Munich Residenz ciborium is just one surviving example of a much wider phenomenon. Thanks for following! (all photos in this thread by @ArthurWestwell) 4/4

*please do not try to remove the portable altar from the ciborium in the Residenz

**but if you do please send me photos of the separated altar, thx