The Church of Saint Mary of the Isle in Douglas, Isle of Man has been granted cathedral status.
A decree from Pope Francis read during the service at the Church of Saint Mary of the Isle in Douglas said the new cathedral would be a symbol of "unity".
The church us now a "co-cathedral" alongside Liverpool's Metropolitan Cathedral of Christ the King.
At the service, the Isle of Man's national anthem, was sung and the Lord's Prayer was recited in the Manx language.
The rare co-cathedral status arises from the merging of both dioceses or when a single diocese spans two distinct civil jurisdictions. These churches stand as the first in the British Isles to share the same bishop.
It follows the recent confirmation of city status upon Douglas, during the Platinum Jubilee celebrations last year.
In attendance was the Archbishop Malcolm McMahon of Liverpool, who had advocated for this change in status. Canons from the Metropolitan Cathedral and bishops from across England and Wales were also presence in a show of unity
In a seminal moment, Archbishop Miguel Maury Buendía, the Apostolic Nuncio to Great Britain, installed Archbishop McMahon in a special chair within the cathedral, adorned with a specially crafted coat of arms, symbolizes the unity between the Liverpool Archdiocese and the Isle of Man.
Parish priest Monsignor John Devine said the occasion had celebrated "the ancient Celtic traditions of the Catholic Church on the island and its links to the church in Liverpool".
It had been a "great day" for families who have been part of the congregation for years, and was a "boost to the catholic community on the island", he said.
Archbishop McMahan said the "landmark occasion" had already "strengthened the bonds of friendship" and had "opened the door for the distinctive faith tradition of the island to be shared with the rest of the archdiocese".
He said the new status "serves as a permanent reminder to the people of the island that they are part of a much greater and universal worldwide church".
"I hope it means a lot to Manx people, it means a lot to us," he added