Even Russian President Vladimir Putin has learned that strong-arm tactics do not work with German Chancellor Angela Merkel. Photo / AP
After 12 years in office, German Chancellor Angela Merkel is regarded as "the most powerful woman in Europe".
And when Germany goes to the polls today, few would bet against Merkel winning a fourth term as Chancellor.
Many credit her longevity to stability in a world that seems increasingly in turmoil. Others point to her willingness to go against her party, throwing open the country's doors at the peak of the migrant crisis.
Some believe her strength lies in her adaptability - swinging between hard politician and "Mutti", the matriarch of her nation.
Whispers in German media suggest the secret to Merkel's success is her "girl camp" - an entourage of right-hand women who have outsmarted the old boys' network and kept their boss in power through "mean girl" tactics. This secretive group is at the heart of Merkel's government.
The best known is Beate Baumann. The 54-year-old Cambridge graduate is said to be the only person, other than her husband, Joachim Sauer, that the Chancellor trusts unquestioningly.
"I need someone who can look after me," Merkel is reported to have said in 1992, when she was appointed Women's Minister in Helmut Kohl's cabinet, and her staff of mostly male civil servants treated her with ill-disguised condescension.
She was introduced to Baumann and the two clicked instantly.
Baumann became Merkel's spokeswoman, before being promoted to chief of staff in 1995. Baumann has been called Merkel's "shadow" but she is every bit her equal.
When Merkel was under pressure during one of her first international conferences and looked on the verge of tears, Baumann reportedly hissed: "Get your act together, woman." Merkel did as she was told.
She is not often physically by the Chancellor's side but the two are in constant contact via Merkel's battered (and encrypted) Nokia.
They favour the same discreet dress code: trouser suits and short hair. Neither has children.
Since 1999, Merkel has also relied heavily on Eva Christiansen, a 47-year-old economist; her speech writer, spin doctor and problem solver. Christiansen is credited with inventing the "Merkel sound", her non-threatening style of talking.
Mutti has surrounded herself with powerful women. Defence Minister Ursula von der Leyen, Education Minister Johanna Wanka, and Julia Klckner, vice-president of Merkel's Christian Democratic Union (CDU) party - a former beauty queen, rumoured to be Merkel's preferred successor - are among the country's most influential politicians.
Their prominence has directly impacted policies, with the Chancellor pushing through measures to help female start-ups and set targets for getting more women on boards.
Of course, Merkel does seek guidance from men, but they are not among her most trusted confidantes.
And like Britain's PM Theresa May, she has had to deal with her fair share of "naughty boys".
Many male politicians have underestimated the Chancellor but even Vladimir Putin knows that strong-arm tactics do not work with Merkel.
So why does Merkel lean so heavily on her girl camp? The answer might not lie, as some have suggested, in her desire to help other women climb the ladder, so much as her own rise to power. In 1999, reports surfaced that Chancellor Helmut Kohl had received illegal party funds. Merkel, then environment secretary, swiftly put into place a carefully orchestrated campaign.
She denounced her former mentor - the man who once called her "mein Mdchen" (my girl) - in an article and aimed to take over leadership of the party. When Kohl heard about her ambitions, he responded dismissively: "No, she can't do it." Ouch.
At the time, the CDU was run by white men from southwest Germany. For Kohl, it had been a no-brainer that the next party leader would be found among them - Friedrich Merz, Roland Koch and Jrgen Rttgers.
Yet, in Germany, these young conservative Catholics were prominent members of what was known as the "altar boy generation".
They held traditional views about the role of women: kinder, kche, kirche (children, kitchen, church).
These men were already running some of the largest of Germany's 16 states, and looked like Kohl's natural successors.
But the rise to power of this vicar's daughter from East Germany spelt the demise of the altar boys. One by one, and with a "Merkevellian" touch, she and her female advisers outmanoeuvred the Catholic old boys' network.
Merkel is no sweet, maternal figure. While appearing outwardly supportive, she and her girl camp allegedly placed media stories that undermined their credibility.
Their tactics led to a showdown with Pope Benedict XVI. As a conservative traditionalist, Bavarian-born Josef Ratzinger was not enamoured by Merkel. When she became CDU leader, one of the Pope's closest confidants, the Archbishop of Cologne, Joachim Meisner, complained she "was living in sin".
Merkel quickly got married but never forgot the insult. In true "mean girl" style, she waited for her moment. When the Pope wanted to readmit a former Holocaust denier into the Church, she denounced the pontiff.
Knowing that the Catholic men in her party were duty-bound to defend him, the altar boys were left exposed as having views that ran counter to the values of modern Germany.
It is all but certain that German voters will hand Mutti another four years, with polls this week giving her close to 40 per cent of the vote. Male politicians should beware.
Merkel's team recently said, jokingly, that she had been reading Playboy to get an insight into the mind of Donald Trump. This mean girl does her homework.