From Sonic Retro
Along with the rest of his rock-like people, Foreman Krag is extremly long-lived, and able to personally remember when his civilization was imprisoned by Argus thousands of years ago. By his own admission, Krag was once a ruthless despot, ruling "with fists of iron over world of rock, ore, and mines." However, after the Kron Colony was conquered by Imperator Ix and the Nocturnus Clan echidnas, the Foreman changed his ways and began to rule fairly - ableit under the watchful eyes of the Nocturnus overlords.
During Chapter 7 of Sonic Chronicles, Krag leads an uprising amongst the Kron to throw off the yoke of Nocturnus oppression. With Sonic's help, the rebellion is successful, and the rock-people become staunch allies in the fight to defeat Ix.