WASHINGTON - Oath Keepers founder Stewart Rhodes was sentenced to 18 years in prison Thursday in the first punishment to be handed down for seditious conspiracy in the Jan. 6, 2021, attack on the U.S. Capitol.

The sentence is the longest given to any of the hundreds of people found guilty of involvement in the pro-Trump riot, and the first to include an enhanced penalty for terrorism. Judge Amit P. Mehta said it was merited by the role Rhodes, a leader in the armed anti-government movement for decades, played in convincing others that they had the right to impose their political beliefs by force.

"You, sir, present an ongoing threat and a peril to this country, to the republic and the very fabric of our democracy," Mehta told Rhodes, saying he had never expressed such a belief about another defendant.

He described Rhodes - who remained insistent that he was being targeted for his far-right political beliefs - as a disturbingly charismatic figure who manipulated followers to bring firearms to the D.C. area and prepare for battle on Jan. 6.

"They, too, are victims, victims of the lies, the propaganda, the rhetoric and ultimately the intention that you conveyed," Mehta said. Noting that Rhodes has continued to spread false claims of election fraud and violent rhetoric in interviews from behind bars, Mehta predicted: "The moment you are released, you will be prepared to take up arms against your government."

The sentencing of Rhodes in one of the most high-profile cases in the Capitol attack is the latest milestone in the investigation, which prosecutors say is the largest in U.S. history and has netted about 1,000 charges and more than 650 convictions.

Mehta on Thursday also sentenced Kelly Meggs, a Florida car dealer and top deputy to Rhodes, to 12 years.

In a lengthy address to the court before the sentence was read, Rhodes, 58, did not dispute that he was a key figure in the right-wing firmament. He cast his conviction as part of a left-wing plot that included the Biden administration, the media and anti-fascist activists.

"I'm a political prisoner, and like President Trump, my only crime is opposing those who are destroying our country," he told the court. Comparing himself to Soviet dissident Alexander Solzhenitsyn, he promised that he would "expose the criminality of this regime" from prison.

He said the Oath Keepers, which at one point claimed tens of thousands of members, were targeted because they had protected Trump supporters from counterprotesters at earlier rallies.

Before Rhodes's punishment, no Jan. 6 defendant who did not assault police had been sentenced to more than eight years in prison, and only one man had been sentenced to more than a decade - Peter Schwartz, who had 38 prior convictions, received just over 14 years after assaulting four officers with a dangerous weapon. Rhodes assaulted no one; in court Thursday, he called the testimony of officers wounded in the riot "heart-rending," but "bizarre" and "offensive" to include in his case.

But Mehta said seditious conspiracy is "among the most serious crimes an individual American can commit," more dangerous than a single act of assault.

The five defendants convicted of seditious conspiracy over the past two decades were all sentenced to at least 10 years on that count. Those defendants were all accused of supporting Islamist terrorist groups. Counterextremism experts say the Oath Keepers and allied groups now pose one of the most significant threats to U.S. national security.

Rhodes launched the Oath Keepers with a pledge to defend the Constitution from federal overreach, recruiting former military and law enforcement who shared his distrust of government. But he and similar activists embraced Donald Trump as a perceived ally and shifted to targeting the president's political rivals on the left.

"Violent rebellion because you don't like the results of an election is anathema to our Constitution," said Mary McCord, who headed the Justice Department's national security division for the first several months of Trump's presidency. "Eighteen years is a significant sentence and sends a strong message of deterrence."

Rhodes, Meggs and four others were found guilty at trials in November and January of plotting to unleash political violence, culminating in the attack on the Capitol as Congress met to confirm the 2020 election results. Three co-defendants were acquitted of that count but convicted of obstructing Congress, among other crimes.

Rhodes and followers dressed in combat-style gear converged on the Capitol after staging an "arsenal" of weapons at nearby hotels, ready to take up arms at Rhodes's direction, prosecutors said. Rhodes did not enter the building but was in contact with "ground team" leader Meggs just before the Florida Oath Keeper led a line of members in military-style tactical gear up the East Capitol steps, where they helped a crowd force entry.

Rhodes testified that they couldn't hear each other and that Meggs went "off mission" by going into the Capitol. Mehta said Thursday that while it was "possible" Meggs acted on his own, it was far more likely he got a "green light from Stewart Rhodes."

Meggs backed up Rhodes by saying he went into the Capitol on his own initiative.

"My mistake is when the event went off track, I did not stick to the plan," Meggs said. "We got swept inside."

Unlike Rhodes, Meggs gave a tearful apology, saying he was "sorry to be involved with an event that put such a black eye on our country" and for using "vile and hateful language." He also apologized to his wife, who joined him at the Capitol and was convicted of obstructing an official proceeding. But he maintained that they were both only there to protect others and that an oft-referenced patch he wore on Jan. 6 - which read "I'm just here for the violence" - was misunderstood.

"I was not there to cause violence, I was not there to instigate violence; I was there to try to keep the violence from happening to anyone," Meggs said.

Mehta told Meggs that his version of events was at odds with the evidence, including that Meggs told other Florida Oath Keepers that he was prepared for death.

"Maybe you were just under the spell of Mr. Rhodes," Mehta said, but "I don't know how anyone can stand here today and say this is just bombast."

Attorneys for Rhodes likewise argued that if the former Army paratrooper and Yale law graduate wanted to fight a civil war, he could have called thousands of armed Oath Keepers to Washington. Instead, only two small groups entered the Capitol and did not bring weapons or assault officers.

"J6 still would have happened just as it did" without the Oath Keepers' presence, defense attorney Philip Linder said Thursday. Nor was Rhodes the origin of claims that the election was illegitimate, Linder said: "He's not the one who started that rhetoric and got the American people ginned up."

Both men asked to be released now, having spent roughly two years in prison.

Rhodes said, as he did at trial, that the Oath Keepers came to Washington as bodyguards for Republican VIPs and brought firearms only to help act as "peacekeepers" in case Trump met their demand to invoke the Insurrection Act and mobilize a private armed group to stop Joe Biden from becoming president.

But prosecutors presented evidence that after networks declared the election for Biden on Nov. 7, 2020, Rhodes asked a chat group, which included Trump confidant Roger Stone and Proud Boys leader Henry "Enrique" Tarrio, "What's the plan?" and shared a Serbian academic's proposal for storming Congress. Over the next two months, Rhodes used his platform as one of the extremist anti-government movement's most visible leaders to amplify Trump's bogus stolen election claims and urge followers to be ready for an "armed rebellion" and "bloody civil war." He pressed Trump both publicly and privately to use the military to hold on to power against Democratic opponents.

The government said the Oath Keepers' words and actions demonstrated tacit agreement to take advantage of the Capitol riot to further an illegal plot proposed in public and private by Rhodes, who warned repeatedly before Jan. 6 that "bloody civil war" was necessary if the election results were not overturned, with or without Trump.

"We will have to rise up in insurrection (rebellion)" if Trump does not act, Rhodes texted one associate on Dec. 10. Four days after Jan. 6, Rhodes was recorded telling another that if Trump was "just going to let himself be removed illegally, then we should have brought rifles," and "We could have fixed it right then and there. I'd hang f---ing Pelosi from the lamppost," referring to then-House Speaker Nancy Pelosi, D-Calif.

"That is terrorism, and it is conduct that threatened and continues to threaten the rule of the law," prosecutor Kathryn Rakoczy said before Rhodes's sentencing.

Mehta referred to the Pelosi comment Thursday, as well as a speech Rhodes gave warning of a potential "bloodbath" after a 2014 armed standoff between ranchers and federal agents in Oregon.

"For years, it's clear that you have wanted the democracy in this country to devolve into violence and you have thought that violence is an acceptable means of accomplishing your ends," Mehta said.

After the sentencing, attorneys for Rhodes said that they were preparing an appeal and that their client would keep speaking out even after being told his public comments helped put him in prison for nearly two decades.

"This case was all about the weaponization of speech by the Department of Justice," defense attorney Ed Tarpley said. "Essentially, they have used Stewart Rhodes's words against him."

Capitol Police officer Harry Dunn, who was defending the building on Jan. 6, was not thrilled by the sentence. "I have a hard time finding joy or celebration in a sentence of 18 years," Dunn said. "I've always thought of accountability as what it takes to deter people from doing it again." Given Rhodes's defiant attitude, Dunn said, "that wasn't enough."

Convicted of seditious conspiracy in addition to Rhodes and Meggs were Roberto Minuta of Prosper, Texas; Joseph Hackett of Sarasota, Fla.; David Moerschel of Punta Gorda, Fla.; and Edward Vallejo of Phoenix.

Convicted of other crimes were Kenneth Harrelson, a former Army sergeant from Titusville, Fla.; Jessica Watkins, another Army veteran and bar owner from Woodstock, Ohio; and Thomas Caldwell, a retired Navy intelligence officer who stayed outside the building but hosted other defendants at his farm in Berryville, Va.

All are to be sentenced over the next nine days except for Caldwell, whose sentencing was postponed to review a defense motion to reconsider some of his convictions.