High Quality Content by WIKIPEDIA articles! The Grand Masters of the Knights Templar during the later 12th and the 13th century used a double-sided great seal which showed a representation of The Dome of the Rock (or a circular dome of the Church of the Holy Sepulchre) on one side, and the Order`s symbol of two knights on one horse on the other side. This design is first attested as in use by Bertrand de Blanquefort, the order`s sixth Grand Master, in 1158, forty years after its foundation, and it remained in use until the dissolution of the order in 1312.