The Trusts, a single entity, is the successor to, and sole beneficiary of, seven charitable funds established between 1948 and 1979 by J. Howard Pew, Mary Ethel Pew, Joseph N. Pew Jr., and Mabel Pew Myrin—the adult sons and daughters of Sun Oil Company founder Joseph N. Pew and his wife, Mary Anderson Pew. Honoring their parents' religious conviction that good works should be done quietly, the original Pew Memorial Foundation was a grantmaking organization that made donations anonymously. The foundation became the Pew Memorial Trust in 1956, based in Philadelphia, the donors' hometown. Between 1957 and 1979, six other trusts were created, representing the personal and complementary philanthropic interests of the four siblings. The Trusts continues to be based in Philadelphia, Pennsylvania, with offices in Washington, D.C., London, and Brussels.