ATLANTA (AP) — Former United States (US) first lady Rosalynn Carter, the closest adviser to Jimmy Carter during his one term as US president and their four decades thereafter as global humanitarians, has died at the age of 96.

The Carter Center said she died Sunday, after living with dementia and suffering many months of declining health. The statement announcing her death said she “died peacefully, with family by her side” at 2:10 pm at her home in the rural south Georgia community of Plains. It said a schedule of memorial events and funeral preparations would be released later.

“Rosalynn was my equal partner in everything I ever accomplished,” Carter said in the statement. “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.”

The Carters were married for more than 77 years, forging what they both described as a “full partnership.” Unlike many previous first ladies, Rosalynn sat in on Cabinet meetings, spoke out on controversial issues and represented her husband on foreign trips. Aides to President Carter sometimes referred to her — privately — as “co-president.”