De Ceremoniis
We know the position of the Forum Bovis thanks to the work "De Ceremoniis", written by Emperor Constantine VII Porphyrogenitus (r. 913–959). He writes that the two imperial processions starting from the Great Palace and directed each year respectively to the Churches of Saint Mary of the Spring and Saint Mocius transited through the square. Based on this information, the Forum should be located in the modern neighborhood of Aksaray.