The most recognizable flag used by the Confederacy during the Civil War was the Confederate battle flag of Robert E. Lee's Army of Northern Virginia, designed by southern firebrand politician William Porcher Miles. The actual official national flag of the Confederacy changed multiple times during the war, from the original "stars and bars" design in 1861 to an 1863 flag that incorporated the more familiar battle flag design on a field of white.
Although it was never the official national flag of the South in the Civil War, the familiar "Southern Cross" battle flag with its 13 white stars has long been the most famous banner of the Confederacy. It was designed by William Porcher Miles, who was on the committee to create a new flag and insignia for the breakaway states. Miles disliked the "stars and bars" flag that was adopted because he thought it too closely resembled the flag of the United States. The battle flag was his own design, and he advocated extensively for its use.
The eventual adoption of the battle flag that Miles designed was based on simple practicality. From a distance, the official Confederate flag looked too much like the Union flag. General Robert E. Lee and his trusted lieutenant, General P. G. T. Beauregard, quickly adopted the battle flag for clarity and its use spread throughout all armies and militia in the eastern theater during the war.
In 1863, the Confederate government decided to redesign their existing flag, incorporating Miles' battle flag "Southern Cross" design in the upper left corner on a field of white. This became the official national flag for most of the remaining war, although most military regiments continued to use the battle flag both in combat and on parade.