Cross-in-square: These churches consist of a crossed square where a cross and the three-parted Holy Bema are inscribed. Based on the connection between these two parts the type is subdivided into the following categories: complex four-columned, semi-complex four-columned, simple four-columned and simple two-columned. This church type appears in Greece during the first half of the 10th century in the katholikon of Panagia in the Monastery of Hosios Loukas in Phocis.