By May 1940 , five more battalions had been formed , all equipped with 10 cm NbW 35 mortars , filling out the sequence from 1 to 8 .
Only the first five were combat ready when the Battle of France began on 10 May 1940 .
By May 1940 , five more battalions had been formed , all equipped with 10 cm NbW 35 mortars , filling out the sequence from 1 to 8 , but only the first five were combat ready when the Battle of France began on 10 May 1940 .