George and Barbara met when she was just 16, and he 17.
"He was the only boy she ever kissed," said Jon Meacham, a historian and presidential biographer, who spoke at the funeral.
Son Jeb Bush said he had a "front row seat to the most amazing love story."
He recalled a recent story of his mother ill in hospital and his father needing to be admitted the next day.
"I think dad got sick on purpose so he could be with her," said Jeb.
He said his ill father sat holding his mother's hand while she slept, with his hair messy and wearing a breathing mask ("he looked like hell"). When Barbara woke up, she looked at her husband and declared, "My god, George, you are devastatingly handsome."