From 1949 to 1955 he was a Minor Canon of Bangor Cathedral.
He died on 18 January 1689, and was buried in Bangor Cathedral.
It is not to be confused with the even older abbey in Wales on the site of Bangor Cathedral.
The present Bangor Cathedral, dedicated to Deiniol, is said to be on the site where his monastery stood.
The organ was originally built by Samuel Green in 1779 for Bangor Cathedral.
David went on to rebuild Bangor Cathedral with a large financial contribution from Gruffudd.
He was buried by the high altar in Bangor Cathedral which he had been involved in rebuilding.
In 1864, he was appointed a canon of Bangor Cathedral.
He became chancellor of Bangor Cathedral in 1851.
He was enthroned in Bangor Cathedral on 24 January 2009.