This article examines the spectacular late Gothic font ciborium in the nave of St. Severus in Erfurt (Thuringia); at over 15 metres in height the largest structure of its kind. Completed in 1467, this intricate microarchitectural edifice rises over an unusual three-sided ground plan and develops in a succession of three tapering openwork storeys, of which the uppermost contains a monumental figure of the Madonna and Child, standing on the crescent moon and enveloped by a mandorla of sunlight. The ciborium was probably commissioned by Hermann Steinberg (appointed Canon of St. Severus in 1464), and not, as had hitherto been assumed, by his younger brother Johannes, in 1467 (still a student at the University of Padua). The craftsman whom Steinberg and the fabrica of St. Severus commissioned remains undocumented, though he was in all likelihood identical with Hans Pfau of Strassburg, Erfurt's cathedral and city architect (Dom- und Stadtwerkmeister) between ca. 1460 and 1473.