The earliest involvement of the Red Shadows in world affairs appears to be the assassination of Archduke Ferdinand, which led to World War I. It is rumored that the Shadows encouraged the assassins and perhaps even trained them. It is unknown what involvement the Shadows had in WWII, if any. Many believe that German style of the Red Shadows soldiers' uniforms links the Shadows with the Nazis, but a connection has not been confirmed.
In the 1960s it was discovered that British MI5 agent Wilder Vaughn was actually an undercover Red Shadows operative. Vaughn would become leader of the Red Shadows in 1970, spearheading the Shadows' most ambitious project to date: the creation of Tesla's "Death Ray." By 1976, the Shadows were nearing the completion of this deadly project. In response, the United States and Great Britain combined forces to stop them. The Shadows were defeated by a coalition of G.I. Joe Adventure Team and Action Force members led by American Green Beret Col. Joseph Colton and British Royal Marine Commando Col. Rupert Pallet. Most of the Red Shadows, including Vaughn, were captured.
For awhile it was believed that the Red Shadows were defeated for good, but that was not the case. In the early 1980s a military leader named Baron Ironblood began to rebuild the Shadows. Inspired by the rise of Cobra Command, Ironblood set out to a create a more paramilitary organization than the Shadows had been previously. During this time period Red Shadows soldiers were seen for the first time as the Shadows became an actual militia. General Pallet was tasked with creating a new Action Force to face this renewed threat. By 1987, Action Force was able to defeat the Shadows, and Baron Ironblood and the Black Major vanished. In reality they had placed themselves in a state of suspended animation, waiting for the future when disciples of the Shadows would awaken them.
In present day America, the Red Shadows have returned. They are now led by an enigmatic figure named Red Serpent. He is joined by James McCullen XXV, the son of Destro and the Baroness. Along with several other nefarious operatives, Red Serpent is determined to wreak havoc across the planet.