German used to be a very popular language among educated people from all over Europe before the 20th century, but after World War I, and especially after World War II, its popularity declined.
It took a few decades for German to regain some ground, but thanks to Germany’s strong economy and high level of education sought after by international students, it is now yet again amongst the most popular second languages in Europe.
The following map shows the current percentage of people who are able to hold a conversation in German (compare it also with the corresponding map for English). It is based on the data contained in the “Special Eurobarometer 386” (the data are from 2012, so Croatia is not included).