BEIJING — A Chinese court sentenced one of the country’s most prominent rights defense lawyers Monday to 4½ years of imprisonment, capping a years-long campaign by the government to shatter a burgeoning civil rights movement that challenged its authority.

Wang Quanzhang was found guilty of subversion of state power, a court in Tianjin said, in what was a relatively light sentence for a figure who played an early role in training grass-roots lawyers and activists to wield the law — and perhaps more worryingly for authorities, social media — in their duels with officials over land seizures, police brutality and the prosecution of banned religious groups.

Wang was the last lawyer to be tried as part of a government crackdown that began July 9, 2015, with the simultaneous arrest of more than 200 lawyers and activists countrywide. The “709” crackdown, as it became known in reference to the date, removed an irritant for the ruling Communist Party while devastating China’s legal profession and rolling back what progress the country had made toward rule of law and judicial independence, international experts said.

Wang’s sentence also wound down a saga that has been a source of international scrutiny and a headache for the Chinese leadership. The announcement came suddenly Monday as many in the country were closing shop for the Lunar New Year observance; authorities had previously timed Wang’s closed-door trial for the day after Christmas in December.

Since 2015, U.N. committees and Western leaders, including German Chancellor Angela Merkel, have repeatedly raised the detained lawyers’ cases during visits with Chinese officials, while several of the lawyers’ wives have attracted international recognition for their advocacy on behalf of their husbands.

In a statement Monday, Wang’s wife, Li Wenzu, said her husband was innocent and criticized the authorities.

“Their arrest, torture, prosecution and sentencing of Wang Quanzhang and the 709 lawyers and citizens were all in violation of Chinese law,” Li said.

Beginning in 2009, Wang was part of a legal-aid network that taught barefoot lawyers and activists across the country how to sue local officials and rally the public for their causes. The government indictment against Wang showed that authorities were particularly incensed by his group’s use of social media and the fact that his associates received training and funding from foreign sources, namely the Swedish activist Peter Dahlin, who was held and interrogated in 2015.

Since popular revolutions spread through the Arab world in 2011, China’s stability-obsessed leaders have been particularly sensitive to dissent on social media and have warned about foreign forces infiltrating China to undermine their rule.

Aside from Wang, Zhou Shifeng, founder of the well-known Beijing law firm where Wang worked, was sentenced to seven years. Hu Shigen, an activist who worked with the group, received 7½ years. A blogger linked to the movement who lampooned Chinese officials on the Internet, Wu Gan, received eight years in December 2017. 

Wang could be eligible for release in one year because he has been detained since mid-2015. He has not been granted access to his family or his appointed attorneys since then.

Wang was tried in a closed-door hearing Dec. 26, but the session ended unusually without a verdict after word emerged that he had dismissed his government-appointed attorney at the start of the proceedings. It is not clear how a judgment was reached or why. Wang’s sentence was announced Monday on the court’s website in a one-sentence statement that did not provide details or judicial reasoning.

Experts on law and human rights in China say Wang’s case is a reminder of how the rule of law has regressed markedly in less than a decade. Among those who were caught in the 709 dragnet, many were disbarred. A legal movement that briefly flourished in the 1980s as China opened up has been snuffed out.

“What we are seeing now, without pretense, is how Xi Jinping has weaponized the law,” Michael Caster, an Asia-based researcher specializing in Chinese human rights and law, said by email. “Arbitrary and secret detention, widespread throughout the 709 crackdown, has been institutionalized in domestic laws and regulations, and the legal profession has been increasingly hollowed out through the arbitrary revocation of lawyers’ licenses and the threat of disappearance.”