When Donald Tusk got a top European Union job, the former Polish prime minister took a crash course in English, going from virtually zero to proficiency in the language in less than a year.

The political folkways of Brussels have proven harder to master for the president of the European Council.

Arriving in town trailed by high expectations from his successful seven-year run atop Polish politics, Tusk’s acclimation to the EU capital has been difficult, officials around him admit.

Along with the rest of the EU, Tusk has struggled with the twin crises of 2015 — Greece and migration. At times, the man who represents the EU’s 28 states in Brussels comes in for pointed criticism over his handling of both.

Critics, from Italian and French officials, to the aides around European Commission President Jean-Claude Juncker, call into question Tusk’s suitability for the job.

“He doesn’t look like he’s happy here,” said a senior official from the Commission, a parallel but larger institution that sits across from the Council on the Schuman roundabout in central Brussels.

The sniping over his performance is more than anecdotal.

In last week’s POLITICO caucus of more than 100 leading policymakers in Europe and America, Tusk was called good or very good by 37 percent of respondents, fewer than every other top leader in Brussels except for Parliament President Martin Schulz. Forty-two percent called Tusk average and 22 percent poor or very poor. Sixty-five percent rated Juncker good or very good.

POLITICO spoke to more than two dozen sources from 10 EU countries for this article. Most requested anonymity, saying they preferred not to speak about Tusk on the record, since they have to work with him and his office.

People close to Tusk acknowledge a slow start and a steep learning curve for their boss in Brussels. But by the summer, they say, he started to come into his own.

As more than one pointedly noted, it was Tusk’s vision and not Juncker’s that carried the day in the critical moments of the Greek and migration debates. And, they add, Tusk deserves credit for keeping the EU united on Russia, quietly extending sanctions this summer without any fanfare.

A ‘forceful’ Tusk

Tusk makes a larger target for criticism than his predecessor, Herman Van Rompuy, the former prime minister of Belgium. His nickname the “Belgian submarine” referred to an important behind-the-scenes role at the Council and a low public profile.

The 58-year-old Pole signaled a politically ambitions agenda in his inaugural remarks last December. As Europe was focused on Vladimir Putin’s aggression against Ukraine, Tusk called on the EU to stand up to its “enemies” and “support those in the neighborhood who share our values.”

From day one, he has tried to make himself out to be a different kind of leader in Brussels.

“Tusk sees his role as going beyond that of only being a broker of compromises,” said an official at the European Council, “as that of being someone who can and should lead the way, when necessary, which sometimes also means more forceful statements.”

His champion for the top job in Brussels was Germany, whose Chancellor Angela Merkel developed a close working relationship with the German-speaking Pole while he headed the government in Warsaw. German officials in Brussels tend to refrain from joining in the criticism of Tusk that others, particularly the French and Italians, share more openly.

North and Eastern European countries on the whole are less critical. “He’s far more assertive on foreign policy than his Belgian predecessor,” Estonian President Toomas Hendrik Ilves said in a recent interview with POLITICO. “I have no complaints — none — about him.”

“Tusk is the only one of the three presidents who fights for a common position and ground of the 28 [EU countries],” said a senior diplomat from an easte European country.

“The other two destroy it with their political ambitions,” he added, referring to Juncker and Schulz, who may be looking to return to Germany to contest the next elections for the Bundestag.

Tusk’s aides say the president ultimately answers to the 28 countries and is above the usual political gossip and backstabbing of the European capital.

“It is a fact that Tusk is not really part of the Brussels bubble,” said the Council official. “This is also a plus and helps him to be more independent.”

The Juncker factor

Yet the European Council head must navigate almost daily the political shoals in Brussels, something that has been an acknowledged challenge for Tusk in his first year.

When the crisis in Ukraine faded out of focus earlier this year, Tusk had to turn from an issue he knew well and bone up on the EU’s current preoccupations that didn’t play to his strengths: the euro and Greece, migration and the coming referendum on British membership in the EU.

Hailing from a country that joined the EU barely a decade ago and isn’t in the eurozone, Tusk came here without the insider’s edge of his closest peer in town, the longtime Luxembourg Prime Minister and Eurogroup President, Jean-Claude Juncker.

“Juncker knows exactly the way the EU works from the inside and he knows exactly the size of the bureaucratic machine,” said Judy Dempsey, a senior associate at Carnegie Europe, a think tank. “He comes from many years of experience.”

The men are cordial together in public yet present contrasts in styles. Juncker is an emotional veteran who’s prone to elaborate public displays of affection. Tusk is cool and reserved, though at a May EU summit in Riga, he could barely disguise his annoyance with Juncker’s effusive greetings of arriving EU leaders. As Tusk looked on, the Commission president slapped or hugged heads of government and on seeing Hungary’s Viktor Orbán blurted out, “the dictator is coming.”

At last week’s EU summit, the leaders as usual appeared together for the concluding press briefing. After one question, both looked at each other, unsure who would answer first. Then Juncker said, “You go first, you’re the boss.” He did so with a smile, leaving few in the room with the impression that Juncker wasn’t the one most at home in this setting. Tusk spoke first.

The jostling with Juncker on substantive EU policies has been the formative experience of Tusk’s first year — who won depends on who you ask. Certainly the early reviews weren’t kind to the Pole.

As Greece careened from the far-left Syriza party’s stunning election win in January to default and near bankruptcy in the summer, Juncker was the most visible leader in Brussels. He called on European leaders to strike a deal, ruling out Grexit, and as Grexit loomed lashed out at Greek Prime Minister Alexis Tsipras.

During those months, Tusk stayed largely out of view, which his critics in town notched up to Poland’s absence from the eurozone and lack of familiarity with EU culture. He came on the scene prominently this summer at the climax of the Greek crisis.

The president’s team says Tusk joined the debate calmly, in contrast to Juncker’s outbursts, urging all parties to calm down (“nobody here is an angel,” he told POLITICO in July.) At the summit a few days later, Tusk was in the room with Merkel and Tsipras to hash out the final deal. Juncker wasn’t.

His defenders consider the summit — which could have tossed Greece out of the euro but ended with a deal on another bailout — a coming of age for Tusk in Brussels.

The critics are unimpressed.

“On the euro, he did nothing apart from calling a meeting at the end,” said an EU diplomat, who asked for anonymity. “He was not the factor for closing the deal” in July, added this diplomat, an unapologetic critic, who credited “the skills of [Tusk’s] press people” for the favorable headlines coming out of the Brussels summit.

Clash with Renzi

Tusk draws most flack for his handling of the migration crisis, particularly from those countries that supported Juncker’s push this year for a system of mandatory quotas to resettle refugees. Officials from those countries see a national Polish agenda in his opposition to quotas.

Hours before the start of a crucial European summit on refugees in June, Tusk tweeted: “No consensus among [member states] on mandatory quotas migrants. Voluntary mechanism only credible with precise & significant pledges by end July.”

Diplomats from Italy and several other countries were furious, saying that Tusk preemptively helped torpedo the plan.

Several east European diplomats in Brussels said it was Juncker’s quota plan that went too far beyond the EU consensus and needlessly provoked the backlash to migration in Hungary and other countries.

By the end of the summer, Juncker’s quota plan had proved difficult to implement, and the focus of EU leaders shifted to finding ways to secure the block’s external borders and keep migrants from coming in the first place, as Tusk had urged for months.

Breaking with the practice of former President Van Rompuy, Tusk uses the invitation letter for EU leaders to attend European Council summits as a platform to spell out his own positions. Ahead of last week’s meeting, Tusk wrote: “The exceptionally easy access to Europe is one of the main pull factors” for migrants.

The letter touched more than one raw nerve by pinning the blame in part on Europe itself. This is his view, not the consensus of the 28 countries. To many EU diplomats who were used to Van Rompuy’s studied neutrality, Tusk’s decision to take political stands is seen as unusual and polarizing, and hurts his ability to broker agreements.

“This is not what a broker does,” said one EU diplomat.

At last week’s gathering, Renzi and Tusk exchanged sharp words over a speech the Pole delivered earlier in October, according to a source in the room.

In an appearance before the European Parliament, Tusk had criticized, in the same sentence, Hungary and Italy for failing to observe EU rules on migration. Budapest has built a fence along its border to keep migrants out, while Rome has long let migrants pass through its territory unhindered en route to northern Europe. Renzi, who later acknowledged the dispute publicly, resented the comparison.

Writing A job description

Tusk’s declaration of an unapologetically political, if not necessarily national, agenda for his office has proved divisive in Brussels.

Part of the problem is the peculiar and undefined nature of his post created by the Treaty of Lisbon only in 2009.

As only the second person to hold the presidency, Tusk is writing his own job description even as he tries to navigate a town and institutions he doesn’t know well.

A former prime minister who was accustomed to higher political circles, Tusk has angered diplomats and parliamentarians by keeping them at arm’s length in Brussels.

“At a Coreper level he is not involved,” said a senior EU diplomat, referring to the regular meetings of ambassadors that lay the ground for the work of the Council. “Van Rompuy at least used to organize regular breakfasts on a rotating basis with ambassadors, but it has never happened so far with him,” the diplomat added.

Unlike Van Rompuy, Tusk has never attended the General Affairs Councils where European affairs ministers prepare the meetings of the European Council, the regular summits of EU leaders.

A Council official replied that other senior officials in the Council “are best placed to ensure the very regular and close contacts with” the representatives of EU countries, adding that Tusk “respects the way the EU works.”

Tusk is grappling with an institutional imbalance created by the Lisbon treaty. Juncker sits atop a bureaucratic machinery of some 34,000 Commission fonctionnaires who can conceive and implement policy. Tusk relies on a group of a dozen close advisers. The civil service at the Council mostly plans meetings and handles translation.

While people close to Tusk know about the criticism around town, they say he’s trying to stay above the local fray. His current mandate for the job, according to a source, is simple: To keep Europe together at a time when it is being pulled apart by numerous different forces.

Matthew Kaminski contributed reporting to this article.