Schallert began his film career in the late '40s, but it was his portrayal of Martin Lane, the father and uncle to the identical cousins on The Patty Duke Show (1963-66), that became his signature role. Schallert's co-star Patty Duke recently passed away on March 29.
In addition to his starring role on the Emmy-nominated sitcom, Schallert also appeared in Leave It to Beaver, The Twilight Zone, Get Smart and the iconicStar Trek episode "The Trouble with Tribbles." More recently, Schallert made appearances on True Blood, Desperate Housewives and How I Met Your Mother.
Schallert is survived by three sons, Joseph, Mark and Brendan, and seven grandchildren. His wife, Leah Waggner, died last year.