She was a petite woman but a huge presence in the life of her son, Michael Bloomberg, who gave away millions of dollars in her name and set aside time from his harried schedule to call her every day. She died at her home in Medford, in the same house where the future mayor and his sister, Marjorie Tiven, were raised.
The mayor announced her death Sunday evening and said that for him and his sister, their mother had been the center of their family.
"Our mother's unimpeachable integrity, fierce independence, and constant love were gifts that profoundly shaped our lives and the lives of so many who knew her," he said in a statement.
Rabbi Tami Crystal once told The Boston Globe that she was "the most beloved member" of the temple.
"Everybody adores Charlotte," Crystal said. "She's a ball of fire."
She was grandmother to Michael Bloomberg's two grown daughters and Tiven's three children. Tiven also works for the city as head of the Commission for the United Nations.
Those who knew Charlotte Bloomberg said she had the energy and sharp mind of someone years younger.
"She's not just a little old lady to sit down and have tea with," said Roy Belson, a friend who was also school superintendent in Medford.
She stood with her son on the steps of City Hall as he took his oaths of office in 2002 and 2006, although her health kept her from his third swearing in last year. During his first two runs, she was along for the ride on the campaign trail. During his 2005 campaign, she was a speaker at a Women for Bloomberg rally.
The proud mom told supporters that day that her son "knows which things are right, which things are good, which things he ought to do."
The mayor often mentioned her, and it was one of his favorite ways to dismiss speculation that he planned to run for president, saying playfully that he had no interest in it but that his mother would be tickled to hear that anyone considered him a contender.
In his 1997 autobiography, he described her as "a woman of liberal views and independent mind" who taught him the value of hard work, intellectual curiosity and ambition to achieve his goals. He remembers the importance she placed on the family dining together each night, and that she set the table with linens, nice serving dishes and proper silverware each night.
"She did for us what my friends' mothers did only for guests," he wrote. The message, he added, was: "We've got to take care of each other."
Charlotte Bloomberg graduated from high school at age 16 and completed her schooling at New York University. After marrying, she stayed home to raise her children while her husband, William Bloomberg, worked as a bookkeeper at a dairy. He had a weak heart and died when Michael Bloomberg was in college, so she became the family breadwinner.
"She taught me you've got to do what you've got to do, and to do it without complaining," Bloomberg wrote.
After he founded the financial information company that bears his name, and began to amass his multibillion-dollar fortune, Charlotte Bloomberg was proud but didn't flaunt the relation.
"Sometimes, when people say to her, `Are you related to THE Bloomberg,' she'll say 'No,' just to avoid the conversation," he wrote.
She once told a reporter that she is most proud of what doesn't make headlines.
"The best things he does are the things that nobody knows about," she said.
Her wealthy son made many donations in his mother's name, including a reported $1 million gift to renovate Temple Shalom's community center, which was subsequently renamed The William and Charlotte Bloomberg Jewish Community Center.
In 2003, he traveled with her to Israel to dedicate a maternity and pediatric center at Hadassah Hospital in her name. To mark her 100th birthday, the family funded a children's center in her name at the Johns Hopkins Hospital in Baltimore.
Michael Bloomberg has also endowed Charlotte Bloomberg funds for various other Jewish causes, and he created a Charlotte Bloomberg professorship in the study of art history at his alma mater, Johns Hopkins University.
The subject, he said, "was something she's interested in and the school needed. To this day, she gets great pleasure knowing the Charlotte Bloomberg Professor is teaching, researching and enhancing our culture."