Analysts frequently predicted it. But when the announcement finally came, it still caused a major shock; after almost two decades as leader of Germany's biggest political party and almost 13 years at the helm of her country, Chancellor Angela Merkel has just announced that she will be relinquishing the leadership of her ruling Christian Democratic Union party by the end of the year, as a prelude to her departure from politics.

Technically, that still means that she can remain head of government until her current mandate expires in 2021. However, few observers believe that is feasible, so her political obituaries are already being published.