There are a total of 6 Leagues to win of which are:
International, English, French, Italian, Spanish & Dutch league. The only league that doesn't have an achievement directly associated with it is the International league tho this league still needs to be won for this particular achievement.
Shortest route to win International league:
Number of teams - 4
Season - Half season
Total Games - 3
Totals games for this achievement - 189 (If you win every league on your first try).
Breakdown - English 38 + French 38 + Spanish 38 + Italian 38 + Dutch 34 + International 3 = 189 Games.