What factors contributed to the rise of the nationalism in the 1810s

Why? Because he completely destroyed the old political division of Western and Central Europe, proving, oddly enough for a military dictator, that the power of repressive or oppressive states can be brought to nothing. In the process he also re-organized borders around, in part along ethnic lines. By doing so, he acknowledged the rights of people to, if not rule themselves, be considered a Nation as such.

Despite being ultimately defeated, his actions in Europe ultimately (among other things of course) led to the contemporary Europe we know today.