His government also began prosecuting some of those figures, in 2008 accusing dozens of people, including retired army generals and journalists, of trying to stage a coup. Mr. Erdogan’s allies called the trial an attempt to reckon with Turkey’s history of violent power struggle. Critics called it an effort to silence the secular opposition.

With voters’ approval in a referendum two years later, Mr. Erdogan reshaped the Constitution again. He said the 2010 overhaul brought Turkey closer to Europe’s democracies and broke from its military past, while his opponents said it gave his conservative government greater control over the military and the courts. He won a third term as prime minister in 2011.

The mall that provoked protests

Mr. Erdogan was not without significant, if disparate, opposition. In 2013, protests that erupted over a proposed mall to replace an Istanbul park morphed into a demonstration of discontent over many issues, including the drift toward Islamist policies and persistent corruption.

Mr. Erdogan cracked down, not just on protesters but also on medics, journalists, activists, business owners and officials accused of sympathizing. Some cultural figures were imprisoned and others fled, and for many who remained, an atmosphere of self-censorship descended.