Why is Angela Merkel so powerful?
6 January 2015 Last updated at 23:52 GMT
German chancellor Angela Merkel will meet David Cameron in Downing Street on Wednesday.
Discussions will focus on the prime minister's plans to renegotiate Britain's membership of the EU after May's general election.
The BBC's Andrew Marr looks at why it is that Ms Merkel is making such a profound mark on the lives of people in Europe.