According to a report on the Latin Mass Society's website:
Various bishops have celebrated the Traditional Mass in various places, but this is the first celebration by a bishop in his own cathedral 'from the throne', that is, in the most solemn form.
Bishop Hopes is used to celebrating the EF; as an auxiliary bishop in Westminster he did this at least annually for the Latin Mass Society for a number of years.
We had been asking for Traditional Masses in Norwich Cathedral for some time, notably for a Requiem for a couple who were parishioners and had left money for this purpose. We were therefore delighted when Bishop Hopes told us, after his appointment to East Anglia, that he would break the ice by celebrating an EF Mass there himself.