Everyone knows the German 6. Army at Stalingrad (probably) - a numbered army. Also, the Corps in the American Civil War were numbered. But when did Armies actually start numbering all their subunits / which country was the first to number their formations?
And were there any notable exceptions after that?
Edit: I feel some more description would be useful:
With leaders names I understand for example A.P. Hills division of the American Civil War. Or the general name of the Armies in that War (Army of the James, the Potomac etc. ), for other, different Naming conventions.
Nowadays, Units are usually Numbered (101. Airborne, 6. Jägerbattalion ...). But when did numbering replace naming?
It began in the 1600s and 1700s with the numbering of Regiments replacing the earlier system in which Regiments were named for their commanding officers or their place of origin (though these were often retained as 'nicknames', if you will). In the 1800s, there was some back and forth over whether Brigades and Divisions were named or numbered, but the Army Corps (an invention of Napoleonic France) was often exclusively numbered in official parlance (however it could also be both named AND numbered, i.e. Longstreet's 2nd Corps, Howard's XI Corps, etc). By the time of the late 1800s through WW1, armies had been thoroughly standardized and Regiments, Brigades, and Divisions were all numbered in the same manner of Corps.