The Chancery of Valyria is one of the Crown Branches that comprises the Crown, itself one of the two Great Powers of Valyria. The Chancery is headed by the Lord Chancellor and employs a body of hired Clerks of the Royal Court. Chancery is responsible for most clerical administrative work that the royal government is tasked with, especially anything dealing with record keeping or the issuing of permits or licenses, such as for foreign merchants. It also deploys envoys on missions of foreign diplomacy and maintains a record of all spoken minutes of official diplomatic missions. Chancery maintains a list of all letters patent it has issued called the Patent Rolls as well as all other legal writs called the Charter Rolls. However, the Exchequer, King's Bench and the Lord Inquisitor also have the authority to issue writs and warrants.

The Court of Chancery also acts as a judicial appeals court for pleas originating from King's Bench, and the Lord Chancellor presides over those trials. Magnates have special rights in the Great Charter that preclude them from being tried by anyone but Chancery, with their peers as jury.

The Chancery also houses the Great Seal of Valyria, which Clerks of the Royal Court make use of in sealing their documents.