The comments here are interesting, lots of possibilities for other ur-languages. My suggestion is macro based languages. Macro based programming predates all programming languages other than ASM[1]. The simple macro systems, like early assemblers provided, aren't ur-languages, but once macros can expand other macros and generate definitions of new macros, the macro systems can become general purpose programming systems.

The two earliest macro systems that were clearly designed to be general purpose languages that I know of are Christopher Strachey's GPM[2] and Calvin Mooers TRAC[3] programming language. These languages appeared at roughly the same time, the mid 1960s. I prefer the syntax of TRAC, but otherwise they are almost isomorphic. TRAC was featured in Computer Lib/Dream Machines[4] by Ted Nelson where the author said it was one of the three important languages for programmers to learn. A good introduction to TRAC and it's implementation can be found in Études for Programmers[5].

Other more contemporary examples of macro programming languages are m4, and TeX. LaTeX is programmed in the TeX macro system.

[1] Daniel Weise and Roger Crew, "Programable Syntax Macros", ACM SIGPLAN, 1993, https://dl.acm.org/doi/pdf/10.1145/173262.155105

[2] Christopher Strachey, “A general purpose macrogenerator,” Computer Journal, 8(3), pp. 225-241, 1965

[3] Calvin Mooers, "TRAC, a procedure-describing language for the reactive typewriter", CACM, Vol 9(3), March 1966, pp. 215-219, https://dl.acm.org/doi/10.1145/365230.365270

[4] Ted Nelson, "Computer Lib/Dream Machines", 1974, Self-published. (There is a 2nd edition from Microsoft Press, but I'm only familiar with the 1st edition).

[5] Charles Wetherell, "Études for Programmers", 1978, Prentice Hall. (It's out of print and available from Amazon for $427. I'm going to have to start locking up my old books.)