When his body passed away, Albert Einstein's brain was surgically removed 7 hours later. It was taken by Thomas Stoltz Harvey, who was the guy that did the autopsy on Albert. Whether he took the brain with permission is still unkown.
In a 1971 biography by Ronald Clark, Einstein said he wanted his brain to be used for research and his body cremated. However, according to Einstein's relatives, that wasn't necessarily true at all and Harvey did indeed take the brain without permission.
Einstein's son, Hans Einstein, did agree to the removal of the brain, but
only for research that would be included in the best scientific
journals.
Mr. Harvey was hoping to study Einstein's brain--to see why he was such a genius. He took pictures of the brain and then dissected it into 240 blocks, which he put into jars. Because of Mr. Harvey's lack of expertise, he never found anything significant.
Harvey didn't only remove Einstein's brain. He took his eyes out and gave them to a dude named Henry Abrams who was Einstein's eye doctor.
A few months later, Mr. Harvey was fired from Princeton Hospital. The reason for his firing was due to the fact that he wouldn't share the brain. Mr. Harvey kept it and took it with him. It was his own personal pet. Slowly, over time, he let bits and pieces be taken by researchers. It wasn't until 1996 when Harvey brought what was left of the brain to Dr. Elliot Krauss at Princeton Hospital, where it remains today.