The first known coat of arms was invented retroactively

The enamel plaque of Geoffrey Plantagenet depicts a coat of arms composed of six golden lioncels on an azure background. This object was long considered the oldest known coat of arms, supposedly offered during the knighting of the count in 1127 by his father-in-law Henry I, King of England. Recent studies have proven that this scene was in reality invented by a monk in the 1170s to project the fashion of his era.