Church of the Holy Trinity   Church of the Holy Trinity is an Episcopal church on Rittenhouse Square in Philadelphia. The first service in the church building, designed by Scottish architect John Notman, was held on March 27, 1859. The corner tower was added in 1867 and was designed by George W. Hewitt of the firm of Fraser, Furness & Hewitt. It is designed in the simpler "low church" style, rather than the fancier "high church" or Anglo-Catholic style of Notman's nearby St. Marks Episcopal Church. Philadelphia's Church of the Holy Trinity is also known for its numerous stained-glass windows, including five by Louis Comfort Tiffany and one by Luc-Olivier Merson. Skylight over the altar The church was listed on the National Register of Historic Places in 1973. Today, the Church of the Holy Trinity's mission is, "In the name of Christ to deepen our faith, to enlarge our community and to act on our beliefs."