Collectively, what are the 12 knights of Charlemagne called?

The 12 peers
The rest of the twelve peers: Anseis, Berenger, Engeler, Gerin, Gerer, Gerard of Roussillon, Oton, Samson, Yvon, and Yvoire: The twelve peers are something like Charlemagne's round table. They are mentioned elsewhere in medieval lore, but the exact list of knights varies. They are brave and loyal to Charlemagne, as well as to each other. They stay with Roland for the dangerous position of rearguard. They fight spectacularly at Rencesvals, slaughtering their twelve Saracen counterparts, but by the end of the battle they are all killed.

Paladins

https://en.wikipedia.org/wiki/Paladin