S. Martin's Church, Canterbury has many claims to be considered one of our most interesting churches, no less on account of its associations than for its structural interest. The date of its building has been a source of endless controversy, as it contains many features attributable to either Roman or Saxon architecture. It is thought that it may possibly have been used for worship by the Christian soldiers of the Roman army. Be this as it may, it is established beyond doubt that it was the oratory of Queen Bertha, the first English Christian queen, who here worshipped, with her chaplain Liudhard, long before the advent of S. Augustine, who himself in later times preached here; and within the walls of this cradle of English Christianity, Ethelbert, King of Kent, the husband of Queen Bertha was baptized. The Venerable Bede, writing within a hundred years of the death of S. Augustine states that there was in 597 A.D. in Canterbury, a church "dedicated to the honour of S. Martin and built while the Romans still occupied Britain." On the departure of the Romans it is probable that the church was still used by a small band of Christian worshippers until the heathen Jutes overran the Isle of Thanet in 449. Little is known of the progress of Christianity on this island from that date until the landing of S. Augustine in 597, and the first fruits of his mission, as we have seen, was the conversion and baptism of King Ethelbert. As one would naturally expect, the aspect of the structure to-day, though suggestive of antiquity, is lacking in uniformity of treatment. The brick courses in the nave are at irregular intervals, varying from nine to twenty inches apart, the spaces being filled with Kentish rag-stone and occasional blocks of chalk. The chancel extends eighteen or twenty feet east of the arch and is composed of Roman bricks, evenly laid and averaging four bricks to a foot. [Illustration: An Ancient Window built with Roman Brickwork. Swanscombe, Kent. _Photograph Mr. G. H. Smith._]