I have always heard that people were a lot smaller centuries ago. This always struck me as odd. When I visited the remains of Pompeii years ago, I indeed noticed that the hardened corpses of the people who died there, were substantially smaller than a normal sized grown-up nowadays.
I've also heard that even Napoleon, who was also depicted as small, was actually about 168 cm (about 5 ft 6 in) which was average during those days, about two centuries ago.
Why does this change in physique appear so drastical in my eyes? Or were people in the northern part of Europe, where I'm from, always as tall as now, due to genetics?
Sampling 187 specimens ranging from the ancient to medieval period in Italy, Giannecchini and Moggi-Cecchi (2008) found that average male height on the peninsula during that time period ranged from about 168cm to 164cm, with the lowest averages during the Roman (republic/empire) period.
164cm is about 5 foot 4 inches. So you would have some significant height over the average Roman. My own interests in Mesoamerican have shown that nutrition can certainly add a few centimeters, but you could still count on being above the crowds, as it were. For heights in other parts of ancient Europe, Noepke & Baten (2008) found their samples of "North-Eastern" European males ranged on average from 169 to 172cm over a similar time scale, so again you'd be above average there.
I should point out though, that the average height for the US current is something like 5'9", and it is only in a very few countries today that 6ft is "average." Furthermore, ancient peoples were not gawking idiots, the concept of "tall" was not a mind-boggling concept then or now.
Very interesting question, which spurs me to ask a follow-up:
I see that it's generally accepted that people were shorter centuries years ago due to nutrition and health conditions, but where does that leave someone like Pier Gerlofs Donia? Would he have been even larger today, and what caused his size? Gigantism and other conditions that we know of and can diagnose today?