The Proud Boys no longer have control over their own name.

Under a ruling by a Washington judge on Monday, the infamous far-right group was stripped of control over the trademark “Proud Boys” and was barred from selling any merchandise with either its name or its symbols without the consent of a Black church in Washington that its members vandalized. In June 2023, the church won a $2.8 million default judgment against the Proud Boys after the organization’s former leader, Enrique Tarrio, and several of his subordinates attacked it in a night of violence after a pro-Trump rally in December 2020.

The ruling by the judge, Tanya M. Jones Bosier of the Superior Court of the District of Columbia, effectively means that Proud Boys chapters across the country can no longer legally use their own name or the group’s traditional symbols without the permission of the church that was attacked, the Metropolitan African Methodist Episcopal Church.

The ruling also clears the way for the church to try to seize any money that the Proud Boys might make by selling merchandise like hats or T-shirts emblazoned with their name or with any of their familiar logos, including a black and yellow laurel wreath.

In a lengthy statement, Mr. Tarrio said the church should have its nonprofit status revoked and Judge Bosier should be impeached. “Their actions are a betrayal of justice,” he wrote, adding, “I hold in contempt any motions, judgments and orders issued against me.”

The initial judgment against the Proud Boys determined that Mr. Tarrio and other members of the group had climbed over a fence surrounding the church, which is just blocks from the White House, and burned a Black Lives Matter banner it was flying. The episode took place after a violent clash between supporters and critics of President Trump.

The church called the Proud Boys’ actions “acts of terror” in its lawsuit and said they had been meant “to intimidate the church and silence its support for racial justice.” A judge agreed, calling the Proud Boys’ conduct “hateful and overtly racist.”

When the Proud Boys failed to turn over any money, lawyers for the church sought to satisfy the judgment by seizing control of the trademarked name and by enjoining the group from “selling, transferring, disposing of or licensing” any merchandise using the words “Proud Boys” or any of the organization’s symbols.

The ruling was handed down as the Proud Boys were riding high after Mr. Trump, in one of his first official acts in his return to the White House, included Mr. Tarrio and several of his lieutenants in his sweeping act of clemency to all of the nearly 1,600 people prosecuted in connection with the attack on the Capitol on Jan. 6, 2021.

Mr. Tarrio, who was serving a 22-year prison term on charges of seditious conspiracy, received a full and unconditional pardon from Mr. Trump. His four co-defendants had their own prison terms commuted to time served.

The banner-burning episode had a dramatic effect on the events of Jan. 6. It led to Mr. Tarrio’s arrest on vandalism charges as he returned to Washington on Jan. 4, 2021. As part of the case brought against him, he was kicked out of the city and was in Baltimore when his subordinates took part in the storming of the Capitol.

On the night the banner was burned, another Proud Boys leader, Jeremy Bertino, was stabbed on the street during a clash with leftist counterprotesters.

One lingering effect of that episode was that it turned the Proud Boys against the police after years of having troublingly close relationships with officers across the country. Another was that Mr. Bertino eventually became a government witness and testified against his compatriots at the trial of Mr. Tarrio and his co-defendants.