In 1964, the Labour Government began to scrap Grammar, Technical  and Secondary Modern schools and bring all children together. All schools were to teach everyone, which is how the name comprehensive, came about. 11+ exams were mostly scrapped  and  people went to their nearest school.
The old GCE exams did not suit everyone, so a new exam  CSE  was introduced. Later, both exams were combined into GCSE  the scheme we have today.