All world leaders, small and great, have a beginning—a sometimes humble origin in which if you saw him or her, you might conclude there was not much to get excited about. Early in their lives, even the greatest personages in history were inexperienced and wet behind their ears, seemingly a mere afterthought before time and events would converge to shine a bright light on them for all to see.

If you had a time machine and you used it to venture decades into the past to find Angela Merkel, you would encounter a very young Angela Kasner. And you might be amazed that someday this awkward, no-nonsense, born-and-bred German girl would one day rise to become the leader of a reunited Germany—and the de facto leader of a united Europe.

During Ms. Merkel’s decade-long tenure as chancellor of Germany, she has managed to steer her nation, with the European continent in tow, through assorted quandaries. Challenges have included threats to Germany and the EU from within, such as the Greek financial crises of 2010 and 2015, and threats from neighbors such as Russia’s forays into the Ukraine. The latest predicament of refugees fleeing war-torn Syria into her prosperous nation is both indigenous and foreign in nature.

Yet, through it all, Ms. Merkel has ensured that Deutschland has remained a force with which to be reckoned.

Ask any teacher, schoolmate and acquaintance from the past, and he or she would tell you Angela was brilliant, analytical, sharp—someone who always strove to bring calm to those around her. Someone who time and again would be underestimated as “weak” and “ineffectual”—only to have those who did so eventually discover they were mistaken.

And all too often, they realized their miscalculation too late.

Humble Beginnings

A shrewd politician with an analytical mind, Angela Merkel was born Angela Dorothea Kasner to Horst and Herlind Kasner on July 17, 1954, in Hamburg, West Germany. With two younger siblings, Marcus and Irene, Angela grew up in the small town of Templin, roughly 50 miles north of Berlin, in the German Democratic Republic (GDR—East Germany).

John Macdougall/AFP/Getty Images

International clout: German Chancellor Angela Merkel and United Nations Secretary-General Ban Ki Moon speak during a joint press conference in Berlin, Germany (March 8, 2016).

Partly of Polish descent via her paternal grandfather, Ms. Merkel was the daughter of a Lutheran pastor who held sympathetic views toward the GDR communist regime (while he believed in the basic idea of socialism, he did not appreciate the way in which it was implemented). The Kasner family was permitted certain freedoms that were typically denied the families of other Christian pastors. They were allowed to easily cross between East and West Germany, for example, and to own two automobiles.

Since children of clergy in East Germany were routinely discriminated against, Angela Kasner’s parents encouraged her to join the communist youth organization, the Free German Youth. They believed it would be the only way that their daughter could taste success in life and attend university.

Though her native language is German, Miss Kasner learned to speak Russian fluently and converse in English as well.

As a teenager, Angela experienced the universal growing pains of youth. But unlike many of her peers, she was never a slave to the whims of fashion and was never desperate to makeover her appearance into Hollywood glamorous. Instead, she emitted a girl-next-door charm.

Former teachers and schoolmates have described young Angela as quiet, plain and mousy—as well as nice, friendly and extraordinarily intelligent. Her former math teacher remembered her as being one of his most gifted pupils. He stated in the BBC documentary “The Making of Angela Merkel (An Unusual Politician)”: “I don’t recall an example where she ever gave up. Surely there were moments when she didn’t get her goal, but when it got difficult and she had a task in front of her which asked too much, she tried to calculate it in reverse.”

After Nazi Germany’s defeat in 1945, the Soviet Union and U.S.-led allied forces divided Germany into two separate states. Berlin was split into two zones, and people could freely cross into each territory. This changed on August 13, 1961, when communist troops in East Germany put up fences and divided Berlin. Barbed wire was replaced with cement blocks, and the infamous Berlin Wall had been erected. Looking back, Angela Merkel described this earth-shattering, historical event as her first political memory.

Angela Kasner learned the necessity of keeping her political views to herself, as did most people who feared drawing the attention of the Stasi, the East German secret police.

She attended the University of Leipzig and studied physics, where she earned her doctorate’s degree for quantum chemistry in 1978. Ms. Kasner then worked as a researcher at the Central Institute for Physical Chemistry of the Academy of Sciences in Berlin-Adlershof from 1978 to 1990, where she was described as a cheerful and open-minded person.

She married fellow physicist Ulrich Merkel in 1977, whom she met at university. Though their marriage dissolved in 1982, she kept her married name. In 1998, she wedded Joachim Sauer, a chemistry professor from Berlin, to whom she has remained married ever since.

Social Revolution

Former U.S. President Ronald Reagan uttered his famous declaration, “Mr. Gorbachev, tear down this wall!” during his 1987 speech at West Berlin’s Brandenburg Gate. Social revolution was in the air, and peoples in both the West and the East could sense it. Ms. Merkel, a 35-year-old physicist when the wall eventually fell in late 1989, was well aware of the commotion but managed to take it all in stride. Her calm demeanor, however, did not reflect the momentous transformation taking place in this part of the world.

By May 1989, communist Hungary began dismantling its border fence with Austria—a move which spurred East Germans to further desire change. Months later, a series of peaceful demonstrations were held in Leipzig, East Germany, with throngs of protesters growing to more than 70,000 people. Though everyone braced themselves for a violent response by the East German police and army, it never came. Soon after, the communist East German leader was forced to leave office. Crowds in Leipzig eventually swelled to 320,000 people.

“East Berliners held their own protest, which would come to be known as the Alexanderplatz demonstration. Some 500,000 to 1 million Berliners came out to demand reform. East German authorities tried to subvert the protests, but there was little to no violence” (“The Berlin Wall, 1961-1989: A Timeline of a Divided Germany,” International Business Times).

On November 9, 1989, a communist party spokesman misunderstood an order regarding travel restrictions, and announced that East Germans were now free to travel directly to the west. His blunder triggered a mass exodus across the Berlin Wall—ultimately leading to the wall’s dismantlement.

“Within a few hours, thousands had gathered at Berlin Wall checkpoints and were demanding to be let through per the order” that had been read (ibid.).

When it became obvious that they could not undo the results of the miscommunicated order, checkpoint commanders allowed growing and swelling throngs to cross over. The wall that divided East and West Berlin beginning in 1961 could now easily be crossed.

Not one to act rashly, Angela Merkel continued her regular after-work routine on that historic night: She visited a sauna with a friend and then went out to treat herself to a beer. Despite her cool exterior, it was clear to Ms. Merkel that politics had become extremely important to her people—and that the two Germanys would soon reunite.

East and West Germany merged into one nation on October 3, 1990. It was hoped that discord, brought on by decades of forced separation during the Cold War, would be erased by unity. Some trepidation about a strong Germany in the post-world-war era remained, however. Fearing the prospect of a newly united Germany, politicians—especially in France—struck a deal that Germany would be allowed to reunify only if it signed the Treaty of Maastricht, an agreement that created the European Union, binding Germany to its European neighbors as a deterrent to war.

Like her peers, who seized the moment to reinvent themselves, Angela Merkel decided to enter the world of politics. She joined a new political party of center-right activists known as Demokratischer Aufbruch (Democratic Awakening). She contributed by helping them unpack boxes and install computer equipment that had just been donated by their fellow politicians in West Germany.

Climbing the Political Ladder

Angela Merkel was eventually elected to the post of deputy spokesperson for the new government, Alliance for Germany, led by Lothar de Maiziere, a lawyer and former professional viola player. Ms. Merkel is described as playing a moderating and balanced role, seeking to appease all parties. She seemed most comfortable acting in the background and had to be virtually pushed to the forefront to take on a leading role as spokesperson. Yet she learned to rise to the occasion and immediately stood out from the cookie-cutter crowd of slick and polished politicians, who were typically obsessed with their attire and personal appearance.

In March 1990, during East Germany’s first and only democratic election, Lothar de Maiziere was elected prime minister and Angela Merkel became his deputy press secretary. In a BBC documentary on Angela Merkel, he recalled the following memory of his protege: “She didn’t seem to care about her awkward appearance at all. She looked like a typical GDR scientist, wearing a baggy skirt…sandals and a cropped haircut. I remember coming back from our first trip and remarking to my female office manager, ‘Couldn’t you go out shopping for clothes with her?’” (The Making of Angela Merkel).

After the unification of East and West Germany, her party merged with the Christian Democratic Union Party (CDU). Ms. Merkel was elected to the Bundestag (the German parliament) and was appointed by CDU party leader and German Chancellor Helmut Kohl to his cabinet as the minister for women and youth. Next, she was appointed to serve as federal minister for environment, conservation and reactor safety. Helmut Kohl specifically wanted someone “quiet” and “female,” preferably a former East German. He routinely called Ms. Merkel his “little girl.”

Other German leaders have commented on the political “aikido”—a martial arts technique that redirects an opponent’s moves against him—of Angela Merkel: “‘At the beginning men tried to humiliate her. They were very authoritarian towards her…’ [German] cabinet minister Ursula von der Leyen told the BBC. ‘She let them have their way, she was very soft, answering in a low voice. Men couldn’t cope with it at all because that was not typical behaviour. She is not pompous, she is very quiet. I think that’s what people like about her’” (Sydney Morning Herald).

Helmut Kohl and his government saw defeat in the 1998 elections. However, Ms. Merkel became the party’s secretary-general. The following year, in the wake of a financial scandal involving Mr. Kohl, she was elected as the CDU’s first female chairperson. The party at large tried to gloss over the embarrassment of the scandal and expected Ms. Merkel to follow suit. Instead, Helmut Kohl’s “little girl” wrote a scathing opinion piece that was published on the front page of Germany’s leading conservative newspaper, which called for her boss’s immediate resignation.

Ms. Merkel lost in the 2002 general elections, but she became the leader of the conservative opposition in the lower house of the Bundestag.

Though her policies were sometimes not favored by the German population, it did not adversely affect Angela Merkel’s overall popularity: the 2005 general elections saw her win the candidacy for the CDU ticket.

In a televised debate seen throughout Germany, in typical bravado fashion, political opponents did their best to belittle Ms. Merkel—attempting to portray her as weak and feckless. But Angela Merkel’s careful, unassuming, calm-cool-and-collected demeanor won over the hearts and minds of the public, who did not appreciate the way in which she had been treated.

Ms. Merkel went on to defeat incumbent Chancellor Gerhard Schroder, thus accomplishing two firsts for Germany: the first female elected to chancellor and the first who grew up in East Germany.

Receiving Acclaim

As chancellor of Germany and effectively the leader of the European Union, Angela Merkel has gained her share of honors from outside her nation. American business magazine Forbes ranked Ms. Merkel at the top of its list of the world’s most powerful women in 2006, 2007, 2008, 2009, 2011, 2012, 2013, 2014 and 2015. Time magazine named the German leader its 2015 “Person of the Year,” and she received India’s Indira Gandhi Peace Prize in 2013.

Though childless, Angela Merkel is popularly known throughout Germany by her nickname “Mutti”—mother of the nation—and is Europe’s longest serving female head of government.

When the financial crisis of 2008 took hold in the United States and throughout Europe, the Merkel administration bailed out Germany’s banking institutions and committed to fiscal austerity to deal with growing debt. This was a true test to her ability to bring calm and composure, a key to stabilizing financial markets.

Chancellor Merkel eventually won a second term. By 2010, under her stewardship, Germany’s economy recovered faster than that of any other country in Europe. Ms. Merkel went on to help craft a bailout for Greece, holding the eurozone together. She said in a public statement: “The euro is the guarantee of a united Europe. If the euro fails, then Europe fails.” And Ms. Merkel won another term to office in a landslide victory.

Ms. Merkel has proven to be bold in her leadership and not afraid to go against the grain. Back in 1994, when she became federal minister for environment, conservation and reactor safety, Ms. Merkel was a scientist at heart, believing that atomic power was the key to her country’s future. But in the wake of Japan’s Fukushima Daiichi nuclear plant disaster, during which a 9.0-magnitude earthquake and resulting tsunami triggered a nuclear meltdown and mass evacuations, Angela Merkel did an about-face.

In 2011, Germany, under her leadership, delivered a shocking statement to the world by declaring that all of the nation’s nuclear power plants would be closed by 2022. This announcement made Germany the largest industrial power to move away from nuclear energy.

By changing her stance regarding nuclear power, Ms. Merkel removed ammo from her critics, especially the Green party.

In a 2013 BBC documentary, Ms. Merkel addressed her critics: “People often accuse me of not acting fast enough. That I let things go on too long. For me, it’s important that I deliberate all options. Different ways of doing it. Running through scenarios, and not simply theoretical experiments in my head. But I also try to live with that decision for a while. I think about it for a whole day, to see how it develops. What it will mean, what people are going to say about it, who’s going to write something about it, who’s going to criticize it” (The Making of Merkel).

Among the tough issues that brought criticism was how Ms. Merkel dealt with Russian policies regarding Ukraine. Some saw Germany’s approach as initially weak, eliciting speculation that Ms. Merkel’s attempts to negotiate with Moscow was a move to alienate the West and appease Russia. Those in the German chancellor’s camp would say her goal was to be patient and deliberate—avoiding a reckless response that could lead to larger conflict.

Refugee Policy

Ms. Merkel’s calming approach was also seen in 2015 when she, against her party’s wishes, accepted increasing numbers of refugees seeking to escape the war-torn Middle East. She went on to urge the rest of the European Union to do the same.

Angela Merkel received high praise from Peter Sutherland, Ireland’s former attorney general, for her response to Europe’s refugee crisis. Ms. Merkel was bold in her declaration that “Europe needs to follow Germany’s example and increase the number of asylum seekers it takes each year” (The Western People).

While addressing widespread fear of allowing hundreds of thousands of Muslims into Germany, she admitted that multiculturalism in her country would never work. Nonetheless, due to the gravity of the situation in Syria, she felt Germany and the rest of Europe must do all it can to open its borders.

The infamous shadow of its Nazi past (death camps, military aggression, the list goes on) still hangs over the German people. Perhaps, as some speculate, both Ms. Merkel’s and Germany’s embrace of foreign refugees in dire need would help absolve national guilt still lingering from World War II.

However, the German chancellor’s refugee policy suffered a major setback in March 2016, as noted by The New York Times: “A far-right party fiercely opposed to Chancellor Angela Merkel’s welcome for refugees made startling gains in three state elections in Germany…dealing the chancellor a blow as she tries to seal a deal with Turkey to reduce the influx of migrants.

“In elections that showed how strongly the refugee crisis has scrambled politics and daily life in Germany, Ms. Merkel’s center-right Christian Democrats failed to wrest control of two states in western Germany where they had once been expected to do so.” The outlet went on to describe Ms. Merkel as “now facing the toughest challenges of her political career.”

Yet setback is nothing new to Angela Merkel. Her response will likely, as always, be the outcome of careful deliberation and resolve on her part.

Opponents, critics and supporters alike can be sure of one thing—Angela Merkel should not be underestimated.