What was it called when the grand army entered moscow to find the city abandoned and set aflame by the inhabitants; retreating in the midst of a frigid winter, the army suffers devastating losses?

This was called as the French Invasion of Russia or was known by the French as the Russian Campaign. This happened on the year 1812 when Napoleon's Grand Armee crossed the Neman River in an attempt to spread the French empire into the Russian hinterlands. The Grand armee was said to be large with able soldiers numbering 680,000. The burning of the city was meant to deny the invaders the option of living off land. These practices by the Russians surprised and disturbed the French, as Russians willingly destroy their own territory and harm their own countrymen. The harshness of the Russian empire immobilized the French and thus the campaign ended with the humiliating defeat of the French which loss most of its able soldiers in that very winter.