Botín is modest, but she is also, indeed, powerful.

A rare, high-profile woman in finance, she’s been a fixture on Fortune’s Most Powerful Women in business list since its inception in 1998 (in February, she landed at No. 41 on our Global list and she’ll rate highly on our Europe Middle East Africa list which debuts next week). She’s on the board of Coca-Cola. She’s established multiple foundations. And yesterday, with her promotion to Global Chairman of Banco Santander (SAN), Santander UK’s parent, the 53-year-old Botín became just one of six women at the helm of a Global Fortune 100 firm (Santander ranked No. 73 on Fortune’s Global 500 in 2014)—and the first woman to chair a global financial organization. “It’s another glass ceiling broken,” says Santander board member and Fortune columnist Sheila Bair.

Botín succeeds her father, Emilio, who died unexpectedly of a heart attack Tuesday and ushers in the family’s fourth-generation of leadership at the 157-year old Spanish bank. Though Banco Santander is a publicly traded company—the Botín family owns a 2% stake—it is described by many as a “family business,” one particularly shaped by Emilio, a charismatic and authoritarian figure, who aggressively pursued expansion and is credited for transforming the Santander from a tiny Spanish repository into one of the world’s largest banks.

Ana Patricia’s appointment was not unexpected. The eldest of six children and the only one in the banking business, she was clearly chosen and groomed by her father to succeed him, says Mauro Guillén, a professor at the Wharton School of Business who has written a book on Banco Santander.

Though some investors have grumbled about nepotism, Botín’s appointment won unanimous board approval. “It was the obvious choice,” says Bair. “She’s smart, she’s savvy, she works hard, and she’s devoted her career to Santander. I can’t imagine anyone better qualified.”

Ana Patricia has held a number of top jobs at the bank and joined its board more than 25 years ago. In 2004, she told Time magazine, “I started at the bottom. Nobody has given me anything.”

Educated at Bryn Mawr College and Harvard University, Botín did a stint at J.P. Morgan before joining Santander, where early on, she was charged with starting up investment banking services in Latin America. The venture was not a success, and though she received criticism, Guillén says the relationships and efforts she made paved the way for the expansion of Santander’s retail banking business in the region.

She later headed Banesto, the Spanish bank, which she is credited for shepherding through the early years of the financial crisis,. Then came the stint running Santander UK, which in four years, she transformed into a highly-profitable and well-run business, says Bair, who notes she has excelled at “recruiting and inspiring talent there.”

Guillén saw Botín’s move to London as “revealing” and speculates it was less a test for her to run a bank than an effort “to get her acquainted with true owners of Santander, or the institutional investors based in London.”

Botín broke up her time at the bank with a period of entrepreneurship in the late ’90s—she started an Internet banking company and ran a private equity fund—which she considers some of the most demanding and rewarding experiences of her career.

Bair describes Botín as prudent and measured like her father; she is also, according to several people interviewed by Fortune, a good listener, communicator and consensus-builder.

“She has lots of experiences, she was very well trained, she’s worked in many different parts of the banking industry,” says Guillén, who emphasizes that Botín is of a different mold than her father. “She speaks several languages fluently. She’s worked on three continents. She’s cosmopolitan.” Now the test is more straightforward: whether she can lead a Fortune Global 100 firm through a turbulent financial era.