Dianne Feinstein, whose decadeslong political career was marked by numerous firsts, has died. She was 90.

“Dianne Feinstein, right from the start, was an icon for women in politics,” former House Speaker Nancy Pelosi (D-Calif.) said in a statement shared with ABC7.

While several Democrats had raised concern about her ability to continue serving in light of several health challenges, Feinstein defied calls to resign.

She was hospitalized as recently as August over a fall in her San Francisco home. Earlier this year, the senator also dealt with a bout of shingles and returned to the upper chamber after nearly three months of absence.

Feinstein became San Francisco’s first female mayor in 1978 after then-Mayor George Moscone was murdered along with City Supervisor Harvey Milk in a case that shook the country. Feinstein, who had been the San Francisco Board of Supervisor’s first female president at the time of the shooting, later became one of the most prominent national advocates for gun control. As a U.S. senator, Feinstein introduced the 1994 bill banning assault weapons nationally.