NoDictionaries   Text notes for  
... uni ex illo contaminatorum grege (nomen Pythagorae fuit) in...

The reference is to the Cleopatra ode of Horace, 1.37.9-10., "contaminato cum grege turpium/morbo virorum." Like Cleopatra, Nero has become the enemy of Rome in the way he uses the city. Later in this book, he will build his "domus aurea" on the ruins left by the great fire.