Lord George Gordon started out as a true British aristocrat: born into Scottish nobility, educated at Eton, lieutenant in the Royal Navy, member of Parliament, head of the Protestant Association.
It was as head of that association that Gordon came to fame. He really didn't like Catholics. In 1780, some 50,000 people followed his lead and staged the so-called Gordon Riots, looting London, destroying Catholic churches and Irish establishments, and marching on Parliament. The army had to be called to put it down.
For his role, Gordon was charged with treason and sent to the Tower of London. After being released, he was jailed once again, this time for defaming the French. (This was in 1788. Should have waited a year.)
In prison once again, Gordon did the only sensible thing: he converted to Judaism! He actually became a pious Jew, kept Kosher, observed Shabbat, and refused to take off his yarmulke even in front of the judge.
Now, some said that Gordon converted to Judaism to help him in business... But considering how he started out, we'll let it slide.