The phrase "to become chancellor" refers to the act or process of being appointed as the head of government in a country that has a parliamentary system, such as Germany. Full definition
Soon after becoming chancellor in 2007, Darling notes that his old ally, newly - installed in No10, now treats him with disdain. (totalpolitics.com)
George Osborne has made several key concessions to the private sector in his first major speech since becoming chancellor. (politics.co.uk)
Almost immediately after Hitler became chancellor on January 30, 1933, Bonhoeffer began to send messages abroad about the German situation. (religion-online.org)