The diocese was established in 1926 as the
Diocese of Waikato, with
Cecil Arthur Cherrington being the first bishop. In 2010, the name of the diocese was changed to the Diocese of Waikato and Taranaki. This reflects the structure of the diocese (since the passage of the
Shared Diocesan Episcopacy Statute 2007), with two bishoprics and two co-ordinary (presiding) bishops. That statute was amended in 2017 (before Hartley's translation) to clarify that when one See is vacant, the other bishop also holds that See as sole diocesan bishop — as has been the case since 2018. With the diocese unable to afford two bishops, Richardson established a commission in December 2018 to review the dual-episcopacy arrangement. == Cathedra ==