Suzanne Nossel, the chief executive of the free expression group PEN America, is leaving the organization, six months after escalating criticism of the organization’s response to the war in Gaza led to the cancellation of its literary awards and annual literary festival.

Nossel will become the president and chief executive of Freedom House, a nonprofit organization based in Washington that promotes democracy and human rights around the world. PEN America announced that it has elevated two current senior members of its leadership team, Summer Lopez and Clarisse Rosaz Shariyf, to serve as interim co-chief executives, effective immediately, with a national search for a permanent leader to follow.

Nossel, a Harvard-trained lawyer, took the helm at PEN America in 2013, after previously working at the U.S. State Department, Human Rights Watch and Amnesty International USA. During her tenure, its membership increased to more than 4,500, while its annual revenue grew to about $25.8 million, up from $4.3 million.

The group, by far the largest of the national PEN International chapters worldwide, also expanded beyond its traditional focus on the literary world, starting initiatives relating to free speech on campus, online harassment, book bans and the spread of state laws restricting teaching on race, gender and other “divisive concepts.”

There have also been flare-ups of intense controversy within the group’s ranks. In 2015, when PEN America announced a decision to give a “freedom of expression courage award” to the satirical French magazine Charlie Hebdo, six writers serving as table hosts withdrew from the annual gala, while more than 200 members signed a letter that criticized honoring a publication that many Muslims in France saw as racist and Islamophobic.

In the aftermath of that controversy, PEN America worked to diversify its offerings and its ranks, while also increasingly emphasizing that free speech is not just about defending the right to speak, but also dismantling barriers that prevent marginalized people from being heard.