The nursery rhyme is not as old as that. It refers to Frederick, Duke of York, second son of George III. He was a commander in the early years of the Napoleonic Wars, but with little success. He made a better administrator however and was C-in-C of the British Army for nearly 30 years. 

Thanks for the information, half of my day was wasted but I did enjoy it, as we say in spain NO PROBLEMO, especially in this heat 40c with 89 percent humidity. At least I was in the air con, then I went for a swim with my dogs. I thought of youy all NOT>