Fitzroy: What's in a Name?

Fitzroy, as all Radio 4 listeners kno, is a region of the Shipping Forecast. It lies between Trafalgar and Sole and was named after Admiral Robert FitzRoy (1805 – 1865). FitzRoy was a pioneering hydrographer, surveyor and meteorologist who commanded HMS Beagle and was a close friend of both Beaufort (of wind scale fame) and Darwin. So the naming of the region is a fitting tribute to this distinguished sailor, who is probably spinning in his grave over the recent record of the Met Office.
But what I wish to write about is the name Fitzroy and how this morning it gave me that Ahh, lightbulb moment. The name cropped up a few months ago when I was reading about Henry VIII and how, in 1536, his bastard son, the popular Henry Fitzroy, Duke of Richmond and Somerset, died unexpectedly (some historians believe Henry was lining him up for the succession at the time). I parked the fact in memory.
Then this morning I was re-acquainting myself with the Duke of Monmouth story, he of rebellion fame who was executed in 1685 under James II. I knew he was the bastard son of Charles II, but discovered that he was also known as James Fitzroy. Wait a minute. Two bastard sons of kings called Fitzroy. Of course! Roy = king; fitz = son of. Tantalisingly obvious, really.
We then discover that King John had a bastard son, known as Richard Fitzroy (1190 – 1246) and that Henry I before him had an illegitimate daughter called Matilda Fitzroy who became an abbess, known as Maud. So it’s a long-standing tradition.
Rewinding to the Duke of Monmouth. He was also the 1st Duke of Grafton, whose grandson Augustus the 3rd Duke was a Whig statesman who served as prime minister from 1768 – 1770. He, in turn, was the grandfather of our original hero Admiral Robert FitzRoy, and so we come full circle in a warmly satisfying manner.