Just to clarify a couple of things Piccs;
The original 14 clubs were;
ENGLAND;- The rags & Liverpool
SPAIN;- Barcelona & Real Madrid.
GERMANY;- Bayern Munich & Borussia Dortmund
ITALY;- Inter Milan, AC Milan & Juventus
FRANCE;- PSG & Marseille.
NEDERLANDS;- Ajax & PSV
PORTUGAL;- Porto
(You only listed 12 clubs)
Though the above clubs had been meeting from the 1980s and had successfully coerced UEFA, via threat of a breakaway league, into giving them the CL in a revised format that allowed them to maximise their profit, they only formalised the group as late as 2000.
In 2002 the group added Arsenal, Bayer Leverkusen, Valencia & Olympique Lyonnaise.
Apart from the revised CL, they had a major success in 2005/6, when they co-signed with Belgian club Royal Charlerois in a court case against FIFA that had implications for UEFA as well. It effectively took away the rights of those 2 institutions to regulate global & European football. They now only have the right to regulate those competitions thet they themselves own.Notice that in recent years, the portfolio of competititions of both institutions has increased dramatically.