WASHINGTON — April 10 is National Siblings Day, and on this Friday, we are sharing photos of celebrities and their siblings to mark the day.

The commemorative day was started by Claudia Evart, who lost two siblings to separate accidents, according to the Siblings Day Foundation. The foundation’s website features letters from U.S. presidents in observance of National Siblings Day, and says it was granted a “Service Mark” in 2007 by the U.S. Patent and Trademark Office.

Browse through these photos of celebrities and their siblings.