4. Angela Merkel

Title: Chancellor of Germany

Country: Germany

Age: 61

With 10 years and three terms in office under her belt, German Chancellor Angela Merkel is a strong and indispensable leader in Europe. She has faced a host of challenges throughout her tenure and come out on top: She helped hold the eurozone together during the financial collapse and global recession, she has stood up to Russian President Vladimir Putin in his aggression toward Ukraine, and, currently, she's managing Europe's refugee crisis. At her hand, Germany stands above the rest of Europe with a strong economy and low unemployment rate. Though she's not universally liked, Merkel has proved a stabilizing force amid turmoil.