William Penn Charter School (commonly known as Penn Charter or simply PC) is an independent school in Philadelphia, Pennsylvania, founded in 1689 at the urging of William Penn as the "Public Grammar School" and chartered in 1689 to be operated by the "Overseers of the public School, founded by Charter in the town & County of Philadelphia" in Pennsylvania. It is the oldest Quaker school in the world, the oldest elementary school in Pennsylvania, and the fifth oldest elementary school in the United States following The Collegiate School (1628), Boston Latin School (1635), Hartford Public High School (1638), and Roxbury Latin (1645).
Principia Cathedra the principals of the chair, from Latin cathedra, as a seat of authority and that which a cathedral's purpose is to indicate the location of such chair.
