This sub-genre denotes a late medieval civilization with futuristic technology.  Imagine if you will,  knights, monks and kings taking part in a conference call. 

Candlepunk has also been called "Castlepunk"and "Middlepunk." It can also be "Dungeonpunk" when adding magical elements, or "Plaguepunk" when describing a plague-ridden candlepunk society. 

Connie Willis' 'Doomsday Book' is an example of Candlepunk.

Assassin's Creed II (probably) and Assassin's Creed (possibly) are also examples of this sub-genre.