Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
IS/1 was the world's first relational database system, implemented at the IBMUnited Kingdom Scientific Centre in Peterlee in the years 1970–1972. It had limited facilities but implemented a true relational model. It was the precursor to PRTV.
References
Notley, M, "Peterlee IS/1 System", UKSC Report 18, 1972
