Disclosed is a method of fabricating a preceramic polymer for making a ceramic material including a metal boride. The method includes providing a starting preceramic polymer that includes a silicon-containing backbone chain and first and second reactive side groups extending off of the silicon-containing backbone chain, reacting a boron-containing material with the first reactive side group to bond a boron moiety to the silicon-containing backbone chain, and reacting a metal-containing material with the second reactive side group to bond a metal moiety to the silicon-containing backbone chain such that the preceramic polymer includes the boron moiety and the metal moiety extending as side groups off of the silicon-containing backbone chain. Also disclosed is a preceramic polymer composition and a metal-boride-containing ceramic article fabricated from the preceramic polymer.