The journey of Structured Query Language aka 'SQL' started way back in 1970 when Dr. E.F. Codd published the paper "A Relational Model of Data for Large Shared Data Banks". This journey definitely deserves great recognition, considering the fact that SQL's relevance and importance never came down, in spite of a plethora of technologies sprouting ever since.
IBM developed SEQUEL (Structured English Query Language) to use in Codd's model. However, Oracle holds the golden credit of releasing the first ever Commercial Relational Database in 1979 implementing what later became SQL.