What it is

The Crown of Justinian is a pedestal item. The in-game line calls it the ancient crown of Emperor Justinian, golden and set with precious stones. The historical-artifact row marks any bookmark year, Royal Court, and the Byzantine emperor as the starting holder.
The same Byzantine set includes the Image of Edessa, a pedestal cloth the row calls the Mandylion, an image of the face of Jesus tied to King Abgar of Edessa. That one asks for a Christian faith and also marks Royal Court.
How to obtain it
Play the Byzantine emperor, or take the empire. In 867 that emperor is Basil I. In 1066 the Byzantine Empire seat is Constantine X Doukas. In 1178 it is Manuel I Komnenos. Alexios I rules between the 1066 and 1178 bookmarks, from 1081 to 1118, and the crown stays with the throne through that reign.
The full effect asks for the Byzantine Empire or the Roman Empire, and for Eastern Roman heritage. A faith with a syncretism tenet for a required religion can still use a religion-locked piece. The Image of Edessa is the Christian piece in this pair.
If the crown is lost, an Adventure inspiration can surface a missing historical artifact. Sponsoring it needs Royal Court or Roads to Power.
What it changes

When the requirements are met, the Crown of Justinian supports monthly renown, domain limit, vassal limit, and court grandeur. If you hold it without the empire and without Eastern Roman heritage, only the court grandeur applies.
The Image of Edessa, on the same starting court, supports monthly piety, a lower cost to build temple holdings and temple buildings, clergy opinion, and court grandeur. Amounts are on each tooltip.
Both are pedestal items. A court shows four pedestal slots. The store image of a Fatimid court is a different set of pedestals. The slot type is the same.
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