Often called the world's most powerful woman, the pastor's daughter, trained scientist and master tactician has outlasted a generation of world leaders, with no obvious successor in sight.
On Tuesday, her conservative Christian Democrats (CDU) are set to re-elect her as party chief, a year after her third election victory put her at the head of a "grand coalition" that absorbed her former adversaries.
The stunning rise of Merkel, 60 -- a twice-married, childless woman from communist East Germany, now often labelled the "Queen of Europe" -- defies political convention.
Her oratory is often monotone, and her awkwardness in front of the cameras has famously led her to adopt a diamond shape pose with her hands, now her trademark.
Her apparent lack of vanity saw her long sporting a bowl-shaped haircut before her advisors sent her off for a style makeover.
Yet it is her air of ordinariness that has made Merkel a hit with German voters.
While she is despised by many in the eurozone as the high priestess of austerity, most Germans value the no-nonsense pragmatism and competence of "Mutti", or Mummy, and prefer her blandness to the charisma of some of her male predecessors.
"She is a kind of mother of the nation," said Berlin political scientist Oskar Niedermayer. "She embodies the common citizen and defends German interests."
Merkel, seemingly indifferent to the trappings of power, lives in a Berlin flat with her rarely-seen scientist husband Joachim Sauer, shops in a neighbourhood supermarket and spends holidays hiking in the Alps.
She is known to detest bluster and machismo, and is accused of lacking a "grand vision", instead operating methodically and mulling problems for days or weeks before taking a stance.
Yet, when polls have signalled swings in the public mood, she has acted boldly -- most notably by deciding to scrap nuclear power after the Fukushima disaster -- which has deprived opposition parties of signature policies and cemented the CDU in the political centre.
Merkel was born Angela Dorothea Kasner in 1954 in the western city of Hamburg, but within weeks her father, a Lutheran pastor, moved the family to a small town in the communist East, at a time when most people headed the other way.
Biographers say life in a police state taught Merkel, who is said to have a mischievous wit in private, the survival strategy of hiding her true thoughts and intentions behind a poker face.
A star student, she excelled in Russian, which she has put to use debating the Ukraine crisis with President Vladimir Putin, who was a KGB officer in East Germany when the Wall fell in 1989.
At the time, Merkel, with a doctorate in quantum chemistry, was working in a Berlin laboratory.
She joined the nascent group Democratic Awakening, which later merged with the CDU, a party was then led by chancellor Helmut Kohl who fondly and patronisingly dubbed her "the girl".
Merkel's political mentor was neither the first nor last politician to underestimate her and pay the price.
When he became embroiled in a campaign finance scandal in 1999, Merkel stuck in the knife, urging her party to drop the self-declared "old warhorse".
The bold move kicked off her own meteoric rise to becoming Germany's youngest ever chancellor in November 2005.
Amid the eurozone crisis, when a battered continent looked to Berlin, Merkel preached fiscal discipline and kept a tight grip on the nation's purse strings, soothing the angst of a thrifty populace fearful about its pensions.
In Athens and Madrid protesters caricatured her with swastikas and a Hitler moustache.
Merkel has defended her policies as "alternativlos", or "without alternative" -- a term much mocked as a rhetorical bludgeon and voted the most offensive word of the year in 2010.
But if Merkel -- who has seen one political system collapse in her lifetime -- is driven by one big idea, it is that Europe's future prosperity is far from certain.
Her mantra is that Europe has just "seven per cent of the world's population, 25 per cent of its economic output, but 50 per cent of social welfare spending".
At home, in a fast-ageing but still wealthy country, Merkel is seen as an assuring rock of stability.
Critics charge she has perfected the art of saying little and avoiding both offence and commitment, while lulling Germany into an apolitical stupor.
"If politics means shaping reality with ideas, then Merkel is not a politician at all," wrote journalist Jakob Augstein. "If politics means staying in power, then Merkel is the best."