There werent really "major" as we know them now, so thats just fictional.
Several teams had phases of dominance in 1.6, beginning with teams like SK or eoL, followed up by coL around 2004 i think leading towards mTw.dk, mouz and fnatic, who battled themselves troughout 2006-2008ish and played the best level of cs ever in my book until today in terms of tactics, teamplay and coordination. If you see IEM World Finals, IEM Dubai f.e. as a major, mouz won several in that spam, so did fnatic/mTw.dk. Golden5 (Pentagram/MeetYourMakers/ESC Gaming and so on) were always around, hard to pinpoint them. There are other teams not named of course.
That went on until cyx died for mouz, which meant the end of this era aswell as players as Sunde/ave retiring for mTw.dk. During that time of the "old guard" stepping away, NaVi took that empty space and dominated the last bit of 1.6, but it wasnt the "best" era anymore in terms of competition, lots of players retired (hard to live by it back then, most studied/worked next to doing that) and new wave of great players came in tho, like karrigan who was a beast.
NaVi was great in their era, but like I said, not the best team ever, not by any scale in terms of winnings, competition and longevity. CSGO came around 2012, so their era wasnt that long in reality. Still love markeloff. <3 My 2 cents.