Rosalynn Carter, former first lady and wife of the 39th U.S. President Jimmy Carter, has died. She was 96.

Rosalynn Carter died at her home in Plains, Ga., on Sunday, the Carter Center announced in a statement. She had been living with dementia and entered hospice care on Friday.

“Rosalynn was my equal partner in everything I ever accomplished,” said former President Jimmy Carter. “She gave me wise guidance and encouragement when I needed it. As long as Rosalynn was in the world, I always knew somebody loved and supported me.”

Rosalynn Carter served as the first lady of the U.S. from 1977 to 1981, and was a leading advocate for mental health, caregiving, social justice and women’s rights in the course of her public life.

Born Eleanor Rosalynn Smith on Aug. 18, 1927, in Plains, Ga., she was the eldest of four children of Frances Allethea Murray and Wilburn Edgar Smith, who died of leukemia in 1940.

While attending Georgia Southwestern College in 1945, she began dating Jimmy Carter, who was home from the U.S. Naval Academy. The couple wed the following year on July 7, 1946, and were married for 77 years.

After Jimmy Carter lost his reelection bid in 1980 to Ronald Reagan, he and his wife founded the Carter Center, a nonprofit organization committed to advancing human rights and alleviating human suffering, in 1982.

In late May, the Carter Center announced that Rosalynn Carter had been diagnosed with dementia, writing, “Mrs. Carter has been the nation’s leading mental health advocate for much of her life. First in the Georgia Governor’s Mansion, then in the White House, and later at The Carter Center, she urged improved access to care and decreased stigma about issues surrounding mental health.”

Rosalynn Carter is survived by her children — Jack, Chip, Jeff and Amy — and 11 grandchildren and 14 great-children. A grandson died in 2015.

“Besides being a loving mother and extraordinary First Lady, my mother was a great humanitarian in her own right. Her life of service and compassion was an example for all Americans,” Chip Carter said in a statement. “She will be sorely missed not only by our family but by the many people who have better mental health care and access to resources for caregiving today.”