Admiral of the Fleet John Arbuthnot “Jacky” Fisher, 1st Baron Fisher of Kilverstone, is considered by some to be the second most important figure in British naval history, after Lord Nelson. An innovator and a strategist who played a key role in taking the Royal Navy from wooden sailing ships to steel-hulled battlecruisers, submarines and the first aircraft carriers, Lord Fisher was apparently also linguistically ahead of his time. As reported by NineMSN:
Lord Fisher used the three-letter abbreviation in a 1917 letter to Winston Churchill in which he complained of negative newspaper headlines during World War I.
“I hear that a new order of Knighthood is on the tapis — O.M.G (Oh! My! God!) — Shower it on the Admiralty!!,” Lord Fisher wrote.
One presumes that the knighthood OMG would rank somewhere below the British rank of OM (Order of Merit) or the OBE (Order of the British Empire.)