Who was "General O'Reilly," and how did a man with such an Irish name become the "Spanish Governor of Louisiana?"

While on a consulting assignment in August of 2000, I was bicycling through the streets of New Orleans and randomly came across a historic marker that read: "Fort St. Charles On Oct. 25, 1769, under Gen. O'Reilly, Spanish governor of Louisiana, were executed French patriots and martyrs: de Lafreniere, Marquis, Noyan, Caresse, Mihet: Vilere having died previously."

The grammar, spelling, and syntax are horrible.  And, I’ve sometimes wondered if this historic marker survived Hurricane Katrina.  Horrible syntax, and ravages of Katrina, not withstanding; I was curious.  Who the **** was "Gen. O'Reilly?"  And how did a man with such an Irish name become the "Spanish governor of Louisiana?"

I made a few inquiries and web searches.  Wikipedia is a pretty good start.

General Alejandro O'Reilly was born in Ireland, but emigrated to Spain with his parents when he was very young.  Later he served with distinction in the Spanish Army, and thereby came to the attention of the Spanish monarch.

King Carlos III appointed O'Reilly as the Governor of Louisiana, with a mandate to quell dissent by French colonists, who were angry that France ceded Louisiana to Spain.  Apparently, O'Reilly arrested the French dissident leaders (most likely the names referenced in the sign), and subsequently had them executed at the foot of what is today called Frenchmen Street ‑‑ the site of the sign I referred to in my opening paragraph.  O'Reilly then earned the unflattering moniker "Bloody" O'Reilly.

So there you have it.