Sen. Dianne Feinstein of California, the oldest senator in the 118th Congress, who previously led Democrats on the Judiciary and Intelligence committees, has died at age 90.

Feinstein died Thursday night at her home in Washington, D.C., her office said in a statement Friday. She had voted as recently as Thursday morning, and President Joe Biden, who served with her in the Senate for 15 years, reflected on her “skillful legislating and sheer force of will” in a statement.

“Often the only woman in the room, Dianne was a role model for so many Americans — a job she took seriously by mentoring countless public servants, many of whom now serve in my Administration,” Biden said. “Dianne was tough, sharp, always prepared and never pulled a punch, but she was also a kind and loyal friend.”

Feinstein, who lost her longtime husband, investment banker Richard Blum, to cancer in early 2022, was frequently absent from the Senate in her final year because of an extended battle with shingles early in 2023. Her fellow Democrats sought to temporarily replace her on the Judiciary Committee during her absence, but it became clear that Republicans would not allow the move.

An establishment Democrat, she was a defender of the institution of the Senate, which caused friction between Feinstein and members of the left wing of her party. But her natural inclination was to seek the middle ground, particularly on politically thorny and complex policy matters.

“I’m probably less an ideologue than I am one for solving the problem of the day, whatever it might be,” she once said, nearly two decades into her Senate tenure. “Most problems around here require bipartisan solutions; therefore, I think working across partisan lines is very important where one can.”

She stepped aside from pursuing the gavel of the Judiciary Committee when Democrats took the majority in 2021, amid recurring questions about her health. Feinstein later declined to seek the office of president pro tempore, a mostly ceremonial title that has traditionally gone to the longest-serving member of the majority party.

Her tenure as chairwoman of the Intelligence Committee made history, though in recent years her profile only increased as a leading voice against the judicial nominations of President Donald Trump, especially the Supreme Court nominations of Neil M. Gorsuch and Brett M. Kavanaugh.

Along with other Democrats, Feinstein denounced then-Senate Majority Leader Mitch McConnell of Kentucky and other Republican leaders for not holding hearings in 2016 on President Barack Obama’s nomination of appeals court judge Merrick B. Garland to fill the high court vacancy.

She voted for all four Supreme Court nominees of Democratic presidents during her decades as a senator.

During her years leading the Intelligence panel, she oversaw an investigation of torture practices during the George W. Bush presidency that led to the production of a controversial but landmark report, and the committee found itself embroiled in a consequential standoff with the intelligence community over the limits of congressional oversight. Committee investigators found that computers they were using to conduct the investigation had been subject to what they viewed as improper monitoring by the CIA.

“This search was not only of documents provided by the committee by the CIA but also a search of the stand-alone and walled-off committee network drive containing the committee’s own internal work product and communications,” she said.

In 2015, she joined most other senators in voting to pass a bipartisan bill to prohibit the National Security Agency’s bulk collection and storage of telephone metadata.

Feinstein was one of the richest members of Congress, thanks in large part to her husband’s wealth. In her final year, a dispute arose about the management of her late husband’s estate.

A trailblazer on gun control

Born in San Francisco in 1933, Feinstein earned a history degree at Stanford University, where she developed a passion for public service as student body vice president.

Following a stint on California’s women’s parole board, Feinstein served on the San Francisco Board of Supervisors.

In 1978, Feinstein became mayor of San Francisco after the assassination of Mayor George Moscone and Supervisor Harvey Milk. She went on to lead the city for 10 years. Feinstein unsuccessfully ran for governor of California in 1990, but she went on to defeat Republican John Seymour in a special election for the Senate in 1992.

Due to her experience in the aftermath of the fatal shooting of Milk, Feinstein was perhaps most closely identified with the issue of gun control.

During the Clinton administration, she was the author of the ban on some semi-automatic weapons, which expired in 2004. Feinstein has sought its renewal, for example, after a gunman killed 26 people, most of them children, at Connecticut’s Sandy Hook Elementary School in late 2012.

Feinstein would speak about gun violence after practically every mass shooting, regularly criticizing congressional Republicans for inaction, as was the case at the beginning of May 2019.

“I authored the assault weapons [ban]. It existed for 10 years. Mass shootings diminished during those times. And yet, now no restrictions and event after event after event,” Feinstein said. “It’s very hard for me to believe that any one of us carry out our responsibility by allowing these kinds of things to happen unchallenged.”

As a senator, Feinstein earned the reputation as a rational legislator who was willing to work across the aisle to develop solutions to problems pertaining to national security, crime, and natural resources.

Until her passing, she also served as the chair of the Appropriations Subcommittee on Energy and Water Development, which controls the purse strings for Army Corps of Engineers as well as the sprawling Department of Energy budget, including California’s national labs.

It wasn’t a forgone conclusion that Feinstein would have such a long tenure.

She squeaked past Republican Rep. Michael Huffington in 1994 to earn a full term in the Senate, but her subsequent reelections were less stressful. She beat Republican challenger Elizabeth Emken by 25 points in 2012.

There had been speculation that Feinstein would retire at the end of her fourth term in 2018, but she opted to run again, ultimately defeating fellow Democrat Kevin de León in the state’s top-two system.