Who becomes chancellor or prime minister of Germany?
The leader of the largest party in the Lower House of the Bundestag becomes the Chancellor, provided that he or she has an overall majority and subject to confirmation by the House. The German system of government, like that of most democracies, isn't keen on a head of the executive who can't get legislation passed. Since the foundation of the Federal Republic in 1949 all governments except one - that of Adenauer from 1957-61 - have been coalitions. Joncey
The role of the Chancellor is similar to that of the British Prime Minister. He/she is head of the administration and responsible (with other ministers) for the day-to-day running of the government. (Since the establishment of the Federal Republic of Germany in 1949 the President's powers have been very limited).
The current chancellor of Germany in 2011 is Angela Merkel from the CDU (Christian Democratic Union) party. Functionally, the Chancellor is elected by the Bundestag (parliament), and must receive a majority vote. While usually a member of the largest political party, it is not a requirement. The German Chancellor position it directly analogous to the English Prime Minister position.