"I've known some deadly professors in my time."
The story of Albert Campion's forays into the fairy tales that are murder mysteries begins around 1930, with assistance from his manservant, Lugg. Lugg was once a burglar, but he knew there was no future in it if he kept getting so fat that the only way out for him was through the front double doors.
At the time we met Lugg in Earth Prime-Time, he was about 55 years of age. (The novels by Margery Allingham do not have anything to do with the Toobworld perspective of her most famous characters.) This means he was born in 1875. And as such he was old enough at sixteen - in 1891 - to have already embarked on his burgling career.
I'm sure there are plenty of deadly professors from the Victorian era whose paths may have crossed with that of Magersfontein Lugg in his home universe of BookWorld. But how many of them in all the fictional worlds could have also been translated into the shared universe of television? I think there's only one who should be considered...
I think Lugg was referring to the Napoleon of Crime, Professor James Moriarty.
I mentioned Lugg at the age of sixteen in 1891 because that was the year in which Moriarty had his final encounter with the consulting detective Sherlock Holmes. Who knows what kind of encounter Lugg had with this deadly professor? Perhaps he was one of the street urchins who worked for Holmes in the loose-knit gang known as the Baker Street Irregulars and Moriarty sent his minions after the lad because of some incriminating information Lugg was trying to deliver to Holmes and Watson.
It's a thought. But since I'm working on a theory that Albert Campion was also the Fifth Incarnation of The Doctor, it doesn't seem so far-fetched.....