Before that Shannon, Bangor Maine and Bahrain were important refuelling points as aircraft simply didn't have the range they do today.
The B747-400 was the game changer as it allowed the middle east to be overflown en route to Asia. Emirates quickly picked up on the fact that with modern aircraft, any point in the world could be reached non stop from Dubai. Therefore any two cities could be paired with a connection in Dubai. Obviously some routes weren't practical but the possibilities were immense.
The aviation landscape is continually changing, with the growth in China and SE Asia, SIN and HKG will be more important as regional hubs and less important as long haul transit points. SIN is building two new terminals and adding a third runway which is presently military only. HKG is expanding the airport and looking at a third runway. BKK, MNL and CGK are presently operating above design capacity.