Merkel begins round 4
Merkel takes the oath of office for the 4th time as Germany's chancellor. Carsten Koall/Getty Images
Angela Merkel took the oath of office for the 4th time on Tuesday, after a protracted coalition standoff that had seemed to imperil her political future was resolved earlier this month. If she stays on through the end of her term in 2021, she will have led Germany for 16 years.
Go deeper: Putting that remarkable longevity in perspective.