Maximilian-Antiqua is a set of open roman caps accompanying Rudolf Koch’s Maximilian, or Maximilian-Gotisch.
There are various digitizations, including versions by Keystrokes a.k.a. Fonts For Design (adding a solid cut), Dieter Steffmann (with ahistoric small caps) and CastleType (as Maximilian CT, misspelled by MyFonts as Maximillian CT, used for sample). Ambrose is a reworked version by Alan Meeks for Letraset.