The 21 gun salute is traced back to early warriors that would lay down their weapons to show they meant no hostility. The salute of firing the guns came to be because cannons were used in the 14th century, and showing their inhostility means firing them once. This rendered them ineffective because they only fired one shot. The number of guns, 7, was linked to biblical significance. The multiple of 3, or 3 shots fired to equal 21, dates back to the mystical significance of the number 3 in ancient civilizations.