author
1837–1915
Best known for Heortology, this German Catholic priest and scholar explored how Christian festivals developed over time. His work blends church history, liturgy, and pastoral insight in a way that still interests readers of religious history today.

by K. A. Heinrich (Karl Adam Heinrich) Kellner
Born in 1837 and dying in 1915, Karl Adam Heinrich Kellner was a German Roman Catholic priest, theologian, and academic. Sources describe him as a scholar of church history and pastoral theology, and records also identify him as a translator.
He is most closely associated with Heortology, his study of the history and development of the Christian festivals and church year. That book helped make his name known beyond German-speaking readers, especially through its English translation.
Although reliable bibliographic and authority sources confirm his dates, fields, and major work, I could not verify many more personal details from the material retrieved here. I also could not confirm a suitable portrait image from the pages examined, so no profile image is included.