(I originally posted the following to the LotFP Facebook group, but I thought I'd save a copy here.)
*Biggest Cities in the West(ish) circa 1500*
Constantinople 550,000
Paris 225,000
Naples 200,000
Antwerp 150,000
Ghent 150,000
Venice 135,000
Adrianople (Edirne) 125,000
Thessaloniki 125,000
Brussels 100,000
London 100,000
Milan 100,000
Moscow 100,000
*Biggest Cities in the West(ish) circa 1600*
Constantinople 700,000
Naples 350,000
Paris 325,000
London 300,000
Venice 200,000
Moscow 200,000
Seville 200,000
Milan 180,000
Adrianople (Edirne) 170,000
Lisbon 130,000
Brussels 100,000
Prague 100,000
Rome 100,000
Amsterdam 100,000
Messina 100,000
Palermo 100,000
(Population figures obviously include a lot of guesswork and estimation.)