Actually, armies long preceded navies in world history. However, they were usually raised on an ad hoc basis; that is, for the duration of a specific conflict. Once that was over, the 'soldiers' would return to their previous activities. The only reason the Royal Navy is called the Senior Service is the fact that it was the first to be established as a 'standing' force; namely one on a permanent footing.
'Forces' was largely a World War II and earlier name which was often replaced by 'Services' in later years. 'Military' is just the latest all-encompassing version of these.