This is a map (pdf-version) based on the numbers published by Erik Zachte, statistics manager of Wikimedia Foundation. It answers to the question which language versions of Wikipedia are mostly visited in a specific country.
At first glance there is no obvious pattern in the map. Still, the countries can be divided into four groups:
* English hegemony
* National hegemony
* Dual hegemony
* Mixed situation
In a number of countries, especially on the Balkans, English is the most read Wikipedia language. In others, there is a national or official language that champions the field, for example in France and Poland. (In the case of Britain, English and the national language are the same.) The third major group consists of the countries where English and the national language both share the hegemonic role (the Netherlands, Norway, Hungary).
The last group, ‘mixed’, contains only a small number of countries, most prominent Belgium and Switzerland, to a certain degree also Bosnia & Hercegovina. These are ethnically/linguistically mixed countries.
Usually, languages learned at school or languages of neighbouring countries do not play a notable role. An exception is Italian in Albania; other cases such as Polish in Lithuania can be explained with ethnic minorities.
The conclusion: Europeans primarily consult the Wikipedia language version in their native language. If that version is weak (and also depending on other factors), they consult the English version.