From what I understand, Chechnya's a region that up until relatively recently had pretty hostile relations with the Russian Federation at large, including two wars. It seems like Yeltsin's failure to resolve the more recent war was a big part of how he fell out of popularity and Putin went back into office? I don't really know the details, but it seems he's managed to smooth things out with them seeing as Kadyrov and other local politicians have been pretty enthusiastic about the war in Ukraine.

Geographically it's situated in the far southwest of Russia, sharing a border with Georgia.