CHICAGO — Jane Byrne, who stunned Chicago’s political establishment in 1979 by taking on the Democratic machine and becoming the city’s first and only female mayor, died Friday morning. She was 81.

Byrne had gradually faded from public view after losing a re-election bid in 1983. She had been in ill health for the last few years and died just before 10 a.m. while in hospice care in a high-rise near the Water Tower downtown, according to her daughter, Kathy Byrne.

Byrne was near a large picture window with a view toward the lake when she died, surrounded by her family, her daughter said.

Byrne said it was “uncanny” that her mother died after the city and the state began honoring her by naming Water Tower Park and the Circle Interchange after her.

“It’s amazing timing,” she said. “That all this happened and now she passed away. But she passed away knowing that all these things occurred and knowing how beloved she was to Chicago. That was nice. It made such a difference.

Tributes poured in within minutes of the news of her death. The Cook County Board of Commissioners held a moment of silence at its morning meeting led by John Daley, the brother of her political rival.

Swept into an office as a reformer, Byrne quickly disappointed many of those close to her who thought she represented a break from the many years of patronage and iron-fisted rule under Mayor Richard J. Daley.

“She was probably not prepared to be mayor, not that you go to school for it,” said Don Rose, who managed her 1979 campaign but later became disillusioned and left the administration. “Although the stories were probably wilder than the actual actions, I think some of her eccentricities were due to the fact that she was just really overwhelmed.”

A creature of the city’s Democratic political machine herself, Byrne became mayor by taking on incumbent Michael Bilandic, a son of Bridgeport who had been ushered into office following Daley’s death in 1976. Some of the credit for her victory went to a winter of heavy snow and the city’s inability to clear streets and keep public transportation moving, especially in minority neighborhoods.

Backed by a coalition of angry blacks, liberals, women and snow-sated commuters, she won the Democratic nomination on Feb. 27, 1979, a guarantee of general election victory in Chicago.

In office, she became known for erratic policies and poorly received publicity stunts like a decision to move with her husband, Jay McMullen, into an apartment in the crime-ridden Cabrini-Green public housing complex on the Near North Side.

Despite her shortcomings as mayor, Byrne was a seminal figure in the city’s history for her successful challenge to a male-dominated culture. She was the first woman commissioner in a major American city. She was the first woman co-chairman of the Cook County Democratic Organization, the powerful and notorious machine that supposedly could elect presidents as well as mayors.

Byrne first got involved in politics when she joined the presidential campaign of John F. Kennedy.

That drew notice by Mayor Richard J. Daley, himself a Kennedy family admirer. The two met in Daley’s office, and Byrne became part of Daley’s vast apparatus.

After paying her dues in the precincts, ringing doorbells, handing out pamphlets and tacking up signs, Byrne joined the Daley team officially in 1965.