Isenheim is a serif family with medieval influences which includes many alternates and ligatures — including some MUFI rarities and lombardic influences.
Isenheim Régulier was originally conceived as a revival from a type found in a small book on the Isenheim Altar Piece by Matthias Grünewald (published by Payot Lausanne in the Orbis Pictus collection sometime in the second half of the XXth century). It became a stand-alone family very far from the original, as if the altar piece slowly merged with the type.