Was a nickname for the Germans in World War 1 'the Bosch'?

yes, this derived from the French that was 'Tête de boche' . Boche was taken to mean 'hard headed' and 'rascal' and was used by the French to describe the German soldiers. (OED). The Word 'boche' seems to come from the German Word 'Bock' which means 'billy-goat' or 'buck'. Colloquially it can imply stubbornness (PONS German Dictionary). I bet you didn't want to know all that