When reading about men like Jean Baptiste Eugène Estienne I often come across terms like infantry general cavalry general or artillery general. But I have never seen an explanation on what this means exactly. Considering the combination of all forces in many battles it would seem unlikely to me that a general can be only concerned with one subtype of the army. Does this mean then that the general rose trough the ranks as for example an artillery officer? I'm hoping someone has an explanation to this.
These terms are generally used to describe two different generals
In terms of the first group of officers, (and taking the British Army as my base) these were men who were initially commissioned into the relevant regiment and corps who then reached General officer rank, then largely ceasing to have any formal ties with their former 'home.' For example, Sirs Douglas Haig and John French are often described as 'Cavalry Generals' in critiques of their leadership during the First World War as they commissioned into cavalry regiments, and possessed considerable previous field experience in leading these formations despite the fact that the formations they led during the First World War were combined arms formations.
In the second group, we have commanders formations orientated towards providing specialised support-such as Army Groups, Royal Artillery (AGRAs) which provided concentrated fire support, or in the case of Army Groups, Royal Engineers, Large scale engineering tasks. These were very large, complex and powerful formations, in the case of the AGRAS often comprising between 6-10 regiments of field, medium and heavy artillery in addition to survey (target acquisition) regiments, or the AGRE deployed on on the eve of Market Garden, which possessed some 20,000 tons of engineering stores, 5,000 men and 3,000 vehicles (of all types). In this case men like Major General George Harrison M.C., who commanded 1AGRA in Italy, could be described as a 'Artillery general' as their role was only orientated towards one purpose.