A noted Columbia University history professor has been kicked out of the classroom for plagiarism.

The Ivy League university found that Charles Armstrong had violated the school’s policies on research misconduct by committing plagiarism in his book on North Korea, according to a university statement.

“There is no higher value at Columbia than ensuring the credibility of our scholarship. Professor Armstrong is no longer teaching or supervising Columbia students,” the university said.

But Armstrong taught for several years after allegations first surfaced in 2016 that parts of his book “Tyranny of the Weak” were lifted from the work of Balazs Szalontai, a professor at Korea University.

Szalontai went as far to create a chart showing nearly 100 instances were he alleged sources in Armstrong’s book were plagiarized or fabricated and called them “grave violations of academic ethics.”

“Indeed, there are cases in ‘Tyranny’ of eyewitness accounts having been altered in a way that the author modified the actual course of events, and arbitrarily changed known facts,” Szalontai contended. “In one such case, for example, the words of a Hungarian diplomat are placed in the mouth of his Soviet counterpart. “

Armstrong, 57, is on sabbatical this academic year and is set to retire at the end of 2020.

The university did not address its delay in taking action.

“I deeply regret the shortcomings of my scholarship and the issues found in my book, which I have done my best to address and correct,” Armstrong told The Post.