Esther Clenott, a longtime public servant and former mayor of Portland who strengthened its sister-city relationship with a Japanese city, died Friday, her family said. She was 91.

Friends and relatives said Clenott, who died of natural causes at a Scarborough hospice, spent her life devoted to her family and her community, first as a Latin teacher in Portland schools and later in elected office, including lengthy service as a Cumberland County commissioner.

“She set a wonderful example,” said Clenott’s daughter, Laurie Kadoch. “Being honest, being a model for what is right, having an open mind, being willing to listen. Values were very important.”

Clenott’s career in public life began in 1986, when she was one of the first women to win election to the Portland City Council, which for generations was dominated by men, said Cheryl Leeman, a former councilor and close friend.

Clenott would go on to spend six years on the council, including two years as mayor, from 1989 to 1990.

A hard worker, Clennot threw herself into whatever she did, Leeman said.

“We shared many moments together, not just professionally and politically, but personally.”

Even though Clennot was a private person, Leeman said they grew close, and would go out together for lunch, and talk.

On the council, Clenott was known to stand up for her beliefs, and was not afraid to let others know when she felt they were wrong.

“I think what most of us enjoyed about her most was her finger-wagging every now and then,” said Leeman. “You could see that classroom kind of stance coming into the council chambers.”

Mayor Michael Brennan, who met Clenott when he was working at the local United Way, where Clenott was a board member, described her as a persistent, hard-working advocate on the council who always pushed for stronger schools.

Her lasting impact, however, was her commitment to strengthen the relationship between Portland and Shinagawa, Japan, a borough of Tokyo.

Under Clenott’s leadership, the cities began a series of cultural exchanges, sending youth sports teams and teachers to the other’s nation.

Clenott was born in Salem, Massachusetts, and graduated from Wellesley College. Her father was a colonel at an Air Force base in Bangor. During college she would take the train from Massachusetts to Maine to visit him.

She met her husband, Martin Clenott, then a student at Bowdoin College, during one of those trips.

They married in 1943, before her husband was shipped overseas to fight in World War II, and before she finished her college degree.

When he returned from the war in 1946, the couple moved to Portland, eventually having three children.

In 1958, Clenott began substitute teaching in the Portland school system. Four years later, she was hired as a full-time Latin teacher at Lincoln Middle School. She spent three years there before moving up to teach at Deering High, where she stayed for 11 years.

She was an active Democrat and became involved in a myriad of causes, among them the local teachers’ union, friends and family said.

After she left the City Council in Portland, Clenott was elected a Cumberland County commissioner, eventually serving for 17 years.

Brennan, at the time a state legislator, remembers Clenott as a vocal and opinionated advocate for stronger county government. When she didn’t like how legislators in Augusta were handling things, Brennan heard about it, he said.

“She kept threatening to run for governor all the time,” Brennan said. “She was really a great woman and a huge contribution to the city of Portland.”

Services are planned for 11 a.m. on Wednesday at Temple Beth El in Portland.