It is with great sadness to share the news of the death of Ron on November 8, 2021.  Born on August 5, 1938 in Youngstown, OH, Ron completed his undergraduate degree at Youngstown State University and earned his M.A. at the University of Chicago and his Ph.D. at the University of Wisconsin-Madison.  He was a noted historical metrology expert with an academic background in medieval history, authoring seven books and numerous articles during his remarkable career.  An esteemed Professor of History, Dr. Z began teaching at Marquette University in 1966, retiring a mere 40 years later and being conferred as Professor Emeritus.  He was defined by the enthusiasm and intellectual rigor he exhibited as a research scholar and in the classroom, receiving the Faculty Award for Teaching Excellence in 1977, the highest honor bestowed upon Marquette University faculty.  Ron was preceded in death by his brothers Ramon (Vonette) and Michael.  He is survived by his cherished wife of 48 years, Kay (nee Monroe); his sister-in-law Patricia Monroe, his daughter Sarah, his nephew Mischa and his niece Michelle and many caring friends.  Visitation will be from 4:00 to 6:00 p.m. followed by memorial service on Friday, November 19, 2021 at Schmidt & Bartelt Funeral Home, 10121 W. North Avenue, Wauwatosa, WI.  In lieu of flowers, memorial donations may be directed to the Ronald E. and Kathleen M. Zupko Endowed Scholarship c/o Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, Attn: Eileen Jennings, to Kathy’s House, see website kathys-house.org, or a charity of one’s choice.  Deep appreciation is expressed for the care and kindness provided to Ron by the staff and medical professionals at Aurora Hospitals and Clinics and St. Camillus Skilled Nursing Facility.