Dedeke completed the Altar of St. Luke (Lukas-Altar) at the Hamburg Mariendom in 1499 for the Hamburg Guild of Saint Luke. It had been left unfinished by his late colleagues Hinrik Bornemann and Absolon Stumme; Dedeke married the widow of the latter man. In 1502 he attained the title of Master of the Brotherhood of St. Thomas. He has been identified with the anonymous "Master of the Halepagen Altar". He died in Hamburg.