Saint Malachy, the great reformer of the Irish church, was consecrated Bishop of Connor in 1124 and remained until his translation to the Archbishopric of Armagh in 1132.

There is much evidence, from written sources and archaeological material, that Connor was a sizeable, complex settlement in the Early Christian period, probably with monastic and secular elements coexisting.

Such was the anti-Anglican tenor of the Scottish settlers that the English divine, Jeremy Taylor, for a time Bishop of the United Dioceses of Down, Connor and Dromore, said of his new home, "I perceive myself thrown into a place of torment."

Because of its larger size, St Anne's Cathedral, Belfast, is shared with the Diocese of Down and Dromore for major church events.

In the 1950s and 1960s rapid slum clearance and suburbanisation saw a number of new parishes created, however demographic changes, movement of people to suburban areas in the Diocese of Down and Dromore and the growth of both secularism and small Evangelical churches saw a decline in membership.

Ecumenism, which since the 1960s has become a steadily more important part of Anglican life in the Diocese, had to be carried out against the background of civil strife in which religion played a major factor.

Shortly after the establishment of Connor as a separate diocese, a grant of arms was obtained from the College of Arms in London in May 1945, blazoned as follows:[1] Azure, a lamb passant supporting with the dexter foreleg a staff proper, flying therefrom a pennon argent charged with a saltire gules, between three cross crosslets Or; on a chief of the last two crosiers in saltire of the field.

The arms were confirmed by the Chief Herald of Ireland in January 2011, although blazoned as follows:[2]Azure between three crosses crosslet or a lamb passant supporting with the dexter foreleg a staff proper flying therefrom a pennant argent charged with a saltire gules on a chief of the second two crosiers of the field.It is based on the traditional County Antrim, including those parts of Belfast west of the River Lagan, and a small part of County Londonderry including Portstewart and those parts of Coleraine east of the River Bann.

"[3] However, the diocesan synod, unlike those in other Northern Dioceses with more strongly Evangelical traditions, failed to endorse a motion on Lambeth Conference Resolution I.10.

[4] Bishop George Davison, elected in February 2020, is seen as theologically conservative, having served previously in the Diocese of Kilmore, Elphin and Ardagh.