The end of the Angela Merkel era has begun.

The German chancellor declared on Monday she would stand down as leader of the Christian Democratic Union (CDU), after the party suffered heavy losses in a regional election in the state of Hesse.

Merkel said she plans to remain chancellor until her term ends in 2021 but will not run for another term as German leader. But giving up the party post will weaken her authority and reinforce the sense that her long reign is coming to an end. It also raises the prospect that her party, or her coalition partners, could push her out of the chancellery sooner.