"In a year where world leaders were tested all through the year, no one was tested the way she was, over and over again," TIME managing editor Nancy Gibbs told NBC's Savannah Guthrie. "The threat to European peace and security really fell to her."

Merkel, 61, is the first individual woman to receive the honor since 1986. Her leadership throughout the economic crisis over the summer and management of issues regarding terrorism and the refugee crisis in Europe were large considerations in the magazine's choice.

"She has stepped up in a way that was uncharacteristic even for her," Gibbs said. "She's been a very long-serving leader, the longest-serving in the west. She controls the world's fourth largest economy, but this year she really was tested in how she would respond to some of the most difficult challenges that any leader is facing in the world."

TIME announced the winner on "The Today Show" Wednesday morning and made its choice from a final field of eight candidates.

Before making the official announcement, the magazine said Monday that Democratic presidential candidate, Sen. Bernie Sanders (D-Vt.) - had won the Readers' Poll for TIME Person of the Year.

TIME's choice for Person of the Year is not always popular and is almost always controversial. The year's nominees reflected that controversy.

The following eight candidates were the finalists for the 2015 Person of the Year:

  1. Abu Bakr Al-Baghdadi - an ISIS leader motivating followers to attack not just in Iraq and Syria but also in places like Tunisia, France — and, possibly, the United States.
  2. Black Lives Matter activists - protesters against inequality and police brutality against African-Americans.
  3. Caitlyn Jenner - a transgender woman who opened a public conversation about gender identity and equality for the LGBT community.
  4. Travis Kalanick - CEO of Uber whose company reached a nearly $70 billion valuation while at the same time raising concerns about the sharing economy.
  5. Angela Merkel - German chancellor who has navigated major news events, including Eurozone economic stress and ongoing migrant and refugee crises.
  6. Vladimir Putin - Russia's president, defiant in the face of Western sanctions in reaction to military activity in the Ukraine and, also, a key player in the fight against ISIS.
  7. Hassan Rounai - Iran's president, trying to bring his country back into the international fold and negotiating a nuclear deal with the West in an effort to spark an economy hit hard by sanctions.
  8. Donald Trump - GOP presidential candidate whose populism has given him frontrunner status in the race while generating debate over the future of the Republican party and the country.