Pat Summitt, who won eight national championships as head coach of the University of Tennessee women’s basketball team and had more wins than any NCAA college basketball coach in history when she was forced to retire at age 59 because of a diagnosis of early-onset Alzheimer’s disease, died June 28 at a senior living home in Knoxville. She was 64.

She died of complications from the disease, said family spokeswoman Erin Freeman.

Ms. Summitt unexpectedly became coach of the Tennessee Lady Vols when she was 22 and, over a 38-year career, formed a dynasty seldom matched in any college sport. She was the first college basketball coach, male or female, to reach 1,000 victories in a career.

She was national coach of the year seven times and was inducted into the Naismith Memorial Basketball Hall of Fame in 2000, 12 years before she stepped down with a record 1,098 victories. She received the Presidential Medal of Freedom, the nation’s highest civilian honor, from President Obama in 2012.

By far the country’s most successful female coach in any sport, Ms. Summitt molded teams and players in her own tough, tireless image. She recovered from a serious knee injury to win a silver medal as a player for the U.S. women’s basketball team in the 1976 Olympic Games, the first time women’s basketball was an Olympic sport.

Eight years later, she coached the U.S. women’s team to its first Olympic gold medal.

Under Ms. Summitt’s guidance, the Lady Vols of Tennessee became one of the most dominant teams in college sports. Her success at Tennessee helped catapult women’s basketball to popularity throughout the sporting world, making it the third-most popular college sport, after football and men’s basketball.

The women’s Final Four in the NCAA tournament now sells out large arenas, and a professional league, the WNBA, has franchises throughout the country.

She accumulated staggering statistical accomplishments while coaching at Tennessee. Her teams made 31 NCAA tournament appearances, playing in the tourney every season she coached after 1982. Her record in the NCAA tournament was 112-23, and Tennessee reached the Final Four 18 times.

Ms. Summitt coached 20 all-Americans and 12 Olympians at Tennessee. Her eight national championships are the third-most in NCAA basketball history, behind only the 11 of Geno Auriemma, coach of the University of Connecticut women’s team, and the late John Wooden’s 10 as coach of the UCLA men’s team.

Legendary Tennessee women's basketball coach Pat Summitt spoke about her battle with early-onset Alzheimer’s disease with The Washington Post's Sally Jenkins in 2011. Summitt's family announced her death June 28. (The Washington Post)

In 1987, she led Tennessee to the first of its eight national championships. Her 1997-98 team, led by all-Americans Chamique Holdsclaw and Tamika Catchings, had a perfect record of 39-0.

In 2011, Ms. Summitt was named Sportswoman of the Year by Sports Illustrated and was featured on the cover with her fellow college basketball coach, Duke University’s Mike Krzyzewski, who was named Sportsman of the Year.

“Pat Summitt is a pioneer in basketball,” Krzyzewski, the winningest men’s college coach of all time, told the Associated Press in 2012. “Her amazing career accomplishments are among an elite group of leaders. Very few people leave a lasting legacy in their chosen professions, and Coach Summitt has done just that at the University of Tennessee and in women’s basketball.”

Ms. Summitt’s coaching career coincided with the growth in women’s sports that took place as a result of Title IX, a 1972 amendment to the Higher Education Act of 1965, which increased opportunities for girls and women in sports.

According to the National Federation of State High School Associations, fewer than 300,000 girls took part in high school sports in 1972; 40 years later, when Ms. Summitt retired from coaching, there were more than 3 million.

At Tennessee, Ms. Summitt led grueling practices that became the stuff of legend. After learning that some of her players had been drinking at a party, she held a practice early in the morning and placed a garbage can at each corner of the court. The women ran laps, one after another, stopping only to vomit into the garbage cans.

At least once, after the team played poorly in the second half of a game on the road, Ms. Summitt ordered her team to put their sweaty uniforms back on after their bus pulled into Knoxville.

“Now, you’re going to play the half you didn’t play last night,” she said, reportedly insisting the players use for practice the smelly clothes that had been locked away in their bus overnight.

She inspired fierce loyalty among her players and went to great lengths to recruit the best basketball players in the country.

Ms. Summitt, who never missed a day of school while growing up in rural Tennessee, required that all of her athletes sit in the first three rows of their classes. She did not allow a single unexcused absence.

As a result, every one of the more than 100 players who completed their athletic eligibility at the university received a degree.

Although she “never raised a placard or a peep for women’s rights,” Sports Illustrated noted in 1998, Ms. Summitt became, by steely example, an “unconscious revolutionary who’s tearing up the terrain of sexual stereotypes.”

An unexpected head coach

Patricia Sue Head was born in Clarksville, Tenn., on June 14, 1952, and grew up on a farm near Henrietta, Tenn. She credited much of her leadership on the court to her parents and the work she did on her family’s farm.

“It’s not done till it’s done right,” she recalled her father saying.

She had three older brothers and, after the chores were done, played basketball with them in the hayloft of the barn. Her family moved to a different school district, where there was a high school that had a girls’ basketball team.

Ms. Summitt was baffled by differences in the rules for girls’ basketball at the time. Teams had six players, but three were placed on each side of the center line, forbidden to cross to the other side.

“We were capable of heavy farmwork, and of absorbing whippings, but for some reason, they didn’t think we could run 94 feet without getting the vapors and passing out or damaging our ovaries,” she said in her 2013 autobiography, “Sum It Up: 1,098 Victories, a Couple of Irrelevant Losses, and a Life in Perspective,” co-written with Washington Post sports columnist Sally Jenkins.

It wasn’t until 1971 that women’s college basketball began to look like the men’s sport, with five players on a team, running the full length of the court.

In 1974, Ms. Summitt graduated from the University of Tennessee at Martin, which she attended without an athletic scholarship because they weren’t yet offered to women. That year, she became an assistant coach of the women’s team at the University of Tennessee’s flagship campus in Knoxville, but when the head coach resigned shortly before the season started, Ms. Summitt was forced to take charge.

Her coaching salary in her first year was $250. She also taught physical education classes, studied for a master’s degree, recruited players and worked out every day to rehabilitate a knee injury. She drove the team van to away games.

She earned a spot as a player on the 1976 Olympic basketball team, and seven months later coached her Lady Vols to the Final Four.

In 1980, she married Ross Barnes “R.B.” Summitt, a bank executive. In her memoir, she wrote about her struggle to have children, saying she endured six miscarriages before giving birth to her son and only child, Tyler.

In her book, Ms. Summitt described making a recruiting trip to Pennsylvania for a top high school guard as her water broke.

“Pat is getting up and going to the bathroom, and coming back in,” said Michelle Marciniak, the player who ended up leading the Lady Vols to their fourth national championship in 1996. “Gets up, uses the bathroom, comes back in. Gets up, uses the phone. And I’m like, ‘Okay, seriously, what is going on?’ ”

Ms. Summitt boarded a plane immediately, and when the pilot suggested they make an emergency landing in Virginia so she could give birth, she scoffed at the idea. She insisted that her son be born in Tennessee.

Her marriage ended in divorce. Tyler Summitt served as the head women’s basketball coach at Louisiana Tech University, one of Tennessee’s longtime rivals, before resigning in April after admitting to an inappropriate relationship that was not specified.

Other survivors include her mother, Hazel Albright Head; three brothers; and a sister.

Ms. Summitt often appeared as a motivational speaker on leadership before groups as dissimilar as Victoria’s Secret and the CIA. She raised millions of dollars for charity and, after announcing in 2011 that she had Alzheimer’s, established a foundation to support research on the disease.

In January 2015, the University of Tennessee announced it would expand the Alzheimer’s wing of the hospital and name it after Ms. Summitt.

In her manner and coaching style, Ms. Summitt often invoked the stern lessons and the work ethic she learned from her father. She never received a hug from her father until she won the national championship in 1996 — her fourth NCAA title.

“I was forty-three years old before my father hugged me for the first time,” she wrote in “Reach for the Summit.” “I had said publicly over the years that he was a forbidding man, and that I’d never been able to win his approval. I guess he got tired of hearing about it.”

Matt Schudel contributed to this report.