By the Crusader period, a cistern under the former basilica was rumoured to have been where Helena had found the True Cross, and began to be venerated as such; the cistern later became the Chapel of the Invention of the Cross, but there is no evidence of the site's identification before the 11th century, and modern archaeological investigation has now dated the cistern to 11th-century repairs by Monomachos.
By the Crusader period, a cistern under the former basilica was rumoured to have been where Helena had found the True Cross, and began to be venerated as such; the cistern later became the Chapel of the Invention of the Cross but there is no evidence of the site's identification before the 11th century, and modern archaeological investigation has now dated the cistern to 11th-century repairs by Monomachos.