“She learned to cloak her purpose in a veil of blandness,” said Constanze Stelzenmüller, a senior fellow at the Brookings Institution who has observed Ms. Merkel as a journalist. Ms. Stelzenmüller, herself raised in West Germany, said Ms. Merkel’s experience surviving East Germany’s authoritarian rule gave her the skills to navigate the male political world she entered as the two Germanys reunited. Ms. Merkel, she said, learned that “you shut up, put up, and watch out for an opportunity, all the while trying not to get hurt.”

Ms. Merkel’s upbringing in East Germany, where most women worked and the state proclaimed gender equality even if patriarchy ruled at home, contributed to a resolution not to make a fetish of feminism. Eager to avoid being reduced to any one label, she expressed surprise that during her 2005 run for chancellor, journalists should ask her about being Germany’s first woman in that job. And at the Group of 20 meeting Ms. Merkel hosted this year, a moderator asked guests who included Ivanka Trump whether they saw themselves as feminists. Ms. Merkel didn’t raise her hand.

Yet she prevailed in Germany’s most stridently masculine party, said Bernd Ulrich, a columnist for Die Zeit who has known her for 20 years. She was a protégée of the long-serving chancellor Helmut Kohl, who referred to her as “mein mädchen,” my girl. Men in her own party derisively nicknamed her “Mutti,” or Mommy, meant as an insult but now adopted by the public as a token of trust. Ute Frevert, Germany’s leading gender historian, observed that Ms. Merkel has resisted all attempts to pigeonhole or condescend to her. (She also declines most interviews.)

“She’s the least motherly person you can imagine, though people want to build a feminine image of her that’s easier to digest,” Ms. Frevert said. Ms. Merkel and her husband, a chemist, do not have children. “But she doesn’t fall into that trap. She doesn’t smile and have a little girly instinct. She’s not a woman playing a man, either. She seems to be gender neutral in a way.”

It is an image she worked hard to foster. Ms. Merkel was mocked early in her career for frumpy dressing and frowsy hair; a car rental company ran an ad depicting her with windblown hair in a convertible, saying she had finally found the right hairstyle. So she adopted her current tidy bob and an unvarying uniform: a bright jacket (chartreuse at the Torgau rally) and sensible pants. She joked that in one of her first government jobs, as environment minister, she realized that people were staring at her shoes instead of listening to what she had to say. To prevent that, she made her wardrobe so predictable that a flurry of articles about the low-cut dress she wore to the opera in 2008 is one of the rare mentions of her clothing in the press.