Archbishop Justin Welby joins new UN advisory board on mediation September 19, 2017 by Fulcrum The Archbishop of Canterbury Justin Welby has joined 17 other global leaders and experts on a new United Nations High Level Advisory Board on Mediation. The board was established by António Guterres, nine months into his tenure as UN secretary-general. ACNS 18 September 2017 FulcrumShareTweetShare