Charter Day was first known as Founder's Day. Think "Happy Birthday William & Mary."
On February 8, 1693, William & Mary's charter was granted by the Crown. James Blair had traveled to Britain to advocate for a university on behalf of his fellow Virginians. After months of networking and seeking support, February 8th is the date under which the charter was issued.
The annual celebration of Charter Day at William & Mary was initiated by President John Stewart Bryan on February 8, 1937.