The “inexperienced college student” (your words on another thread) clearly is not studying British constitution or government and politics.
No, had mentioned the fact that there have been four versions of Greater London government because there have been four, not two:
(1) 1965-1986 Greater London Council with 100 councillors (numbers reduced over the years) plus a separate special district for education (ILEA) for part of its area with some GLC councillors sitting on it;
(2) 1986-1990 Greater London Council disbanded, but Greater London retained, with the councils powers transferred to quangos. ILEA retained with its councillors directly elected;
(3) 1990-2000 ILEA was scrapped, its education responsibilities transferred to the boroughs in its territory;
(4) 2000- directly elected mayor and a toothless, 25 member, Greater London Assembly established.
The ILEA was not directly part of the government of Greater London, it was a quango (but still part of the GLC, like London Transport) that ran education within Inner London (in other words the former LCC area), this was due to the fact the LCC was responsible for education, yet its successor the GLC had that power removed, so I would not count no 3, so there have been 3 versions of Greater London Government which are:
1: Greater London Council (1965-1986) (11 years)
2: Nothing (in its place various quangos, with some powers transferred to local boroughs) (1986-2000) (14 years)
3: Greater London Authority (2000- ) (13 years)
As for the reasons why it has been changed twice well the answer is simple:
From 1 to 2: Because the GLA was a Labour-run pain to the backside for Maggie and the Tory run Westminster, so to get rid of their biggest enemy they abolished it, in other words nothing more than cynical political strategy
From 2 to 3: Of course it turns out to be a massive catastrophic mistake, because it left London runs without any sort of co-ordination strategy, not good when you have 7 million people to deal with, so they brought it back, of course it will was a labour (and later Tory) run pain to the backside for the Labour (and later Tory/Lib Dem) run Westminster
The problem with Greater London is not because it a bad idea, but with the fact it does not cover the entire urban area, metropolitan area and commuter bet and the fact it has nowhere near the amount of powers and autonomy it needs…