The history really has been one of evolution. The very first Parliament was, in fact, only one chamber, largely the House of Lords. The House of Commons split off in the 13th or 14th century. Then we had an alternative, the Committee of the Whole, which was developed, I think, in the 17th century. Parliamentary privileges were anchored in Parliament by the end of the 17th century. Ministerial government came into being in the 18th century. The constitutional principle of responsible government came in towards the end of the 18th century and was confirmed through actions in the early 19th century.
On April 21st, 2020. See this statement in context.