Thessaloniki’s church “St. Demetrius” is a five – nave basilica. It is the – largest religious building in the city and one of the largest in Greece. The church keeps the remains of St. Demetrius, who was born in Thessaloniki. A small church was built in 324 AD, when Emperor Constantine stopped the persecution against Christians . in 413 AD the church was built in its present form due to the transformation of the city into a religious center. Parts of the first church are preserved under its foundations.