Career
Perhaps this Marianus was a different one from the one who received a letter from Pope Gregory VII in 1073. Similarly, the Cronaca sarda makes Marianus the son of Andrew Tanca. The exact identity and relationships of this judge remain a matter of dispute.
Not only did Marianus make a donation to Montecassino, but he benefited the local churches as well and paid an annual sum to the papacy.
He was an ally of the Republic of Pisa.