The Distinctive Unit Insignia (DUI) of the 121st Engineer Battalion, Maryland Army National Guard was approved on 8 June 1954. The black and yellow ordinary in the mid-portion of the shield is called a fess, with the zig-zag partition line on top (a dancetté or dancetty in heraldric terms) and the bottom wavy partition symbolizing the mountains and shore regions of Maryland, places where most of the Battalion’s companies were located. The design of the fess is adapted from the Seal of the state of Maryland, the unit’s home area, with the pick and bayonet in the chief of the insignia alluding to the Engineer branch. The unit motto, PRAEVIUS, is a Latin word that translates into English as “Going Before.”
There can be some confusion regarding which 121st Engineer Battalion this insignia is designated for because there have been two organizations with that title and another with the same numeric and branch designations. The original unit was created through the March 1942 redesignation of the 121st Engineers, District of Columbia National Guard as the 121st Engineer Battalion, an element of the 29th Infantry Division. That unit was reorganized and redesignated as the 121st Engineer Combat Battalion, an element of the 29th Infantry Division, on 1 October 1943. For its service during the D-Day landings and subsequent actions, the Battalion was tapped for a Presidential Unit Citation, a Meritorious Unit Commendation, and a French Croix de Guerre with Palm. But this Battalion was inactivated in January 1946, six-and-a-half years before this insignia was approved.
That is how we know that this DUI is for a second 121st Engineer Battalion that was established in the Maryland National Guard (later redesignated as the Maryland Army National Guard) in 1948. It served as the 29th Infantry Division’s Engineer Battalion until the Division was inactivated in 1968 and remained a part of the Maryland ARNG until its own inactivation in 2006.
Another related unit, the 121st Engineer Regiment, is found in the Maryland Defense Force, a volunteer uniformed state military agency under the command of the Maryland Military Department. The Regiment’s insignia is based very closely on the DUI of the Maryland ARNG unit, differing only in the background color of the chief (blue instead of red) and an Army Corps of Engineer branch insignia below the fess.
Still active as of January 2022, the 121st Engineer Regiment was established in the Maryland Defense Force very shortly after the Maryland ARNG’s 121st Engineer Battalion was inactivated in 2006.