A board of directors whose responsibility includes overseeing more than 100 trusts administers City Trusts of Philadelphia. Referred to as the Sundry Trusts, each trust is maintained separately and administered according to the terms of the benefactor. The board of directors is appointed by and accountable for its actions to the Judges of the Courts of Common Pleas of Philadelphia. Its membership consists of 12 citizens of Philadelphia, and the mayor and the president of City Council, who serve ex-officio. The treasurer of the City of Philadelphia serves as treasurer of the board. Stephen Girard, founder of Girard College, created the largest trust left to the City of Philadelphia. The revenues generated by the investment, real estate and mining operations of Girard Estate support 90% of the funding for Girard College.