This article briefly surveys the historical evidence of Byzantine deaconesses and trends in modern research on the order. By drawing attention to the detrimental effects of research bias, the value of an historical theology of deaconesses becomes clear. The diaconate, like all the major orders, evolved throughout the early Christian period reflecting an adaptation to changing circumstances. Historical deaconesses should be interpreted by the theology of their own time and place, rather than through the lens of the more limited liturgical role of the modern diaconate. Does theological continuity exist between the apostolic diakonia and the ordination and vesting of deaconesses in the eighth century? An historical theology of this enigmatic, yet canonical ministry will reveal the varied iterations of deaconesses extended the ministry of the apostles and bishops into women's spheres in a manner consistent with the Church's enduring theology and mission.