The earliest western Confederate battle flag was flown in Hardee’s Corps of the Army of Tennessee. It had been designed by General Simon B. Buckner and first issued to his troops in January of 1862, who were part of the Army of Central Kentucky based in Bowling Green. It first saw action at Ft. Donelson where some of Buckner’s Division had been transferred. What remained of the army after this transfer became General William J. Hardee’s Corps, which retained the flag.
It’s simple design of a blue field and a white center became known as Hardee’s Battle Flag. Each Unit’s flag were soon inscribed with names of battles they fought in. Later versions had white borders all around.