https://www.grunge.com/825154/did-napoleon-really-shoot-off-the-great-sphinxs-nose/
Despite the historical legend that Napoleon Bonaparte’s men shot off the Sphinx’s nose with a cannon when they rolled through the region in 1798, we know for certain that the French military leader wasn’t responsible, according to Egypt Today. We know this because a painting from 1737 — a half a century before Napoleon and his men came calling — shows the stone beast without its nose.
What is believed to have happened, according to Mental Floss, is that a religious zealot and devout Muslim named Muhammad Sa’im al-Dahr was put off by the practice of area peasants making sacrifices to the Sphinx in order to prevent floods. Believing this to be an unacceptable act of idolatry, al-Dahr is said to have deliberately chopped off its nose with a hammer and chisel some time in the 14th century.
I hadn’t heard that legend. Which makes the scene in the movie make more sense. Clearly Ridley having a little fun with legend, and also a way to reference how little care European officials had for the historical artifacts they were having wars around, or just outright looting. He is British and I think sometime during Gladiator’s run got a private tour of the British Museum. They definitely would have blown up the pyramids if they got in the way.