Amazon founder and multi-billionaire Jeff Bezos is mourning the loss of his mother, Jackie Bezos, who died after a long battle with dementia.

Jacklyn ‘Jackie’ Bezos, mother of Amazon founder Jeff, has died aged 78, after a five year battle with progressive neurological disorder Lewy body Dementia. The billionaire shared a heartfelt tribute on Instagram on Thursday after the news was confirmed in a statement from the Bezos Family Foundation.

Jackie Bezos, a fierce protector of her son Jeff before he founded Amazon.com and a deep-pocketed advocate for early childhood education, has died. She was 78.