Historically, the first true GUT which was based on the simple Lie group , was proposed by Howard Georgi and Sheldon Glashow in 1974 [REF].
The acronym GUT was first coined in 1978 by CERN researchers John Ellis, Andrzej Buras, Mary K. Gaillard, and Dimitri Nanopoulos, however in the final version of their paper[REF] they opted for the less anatomical GUM (Grand Unification Mass).