Reigning European champions Munster will face Sale Sharks and two French teams in the group stages of next season's Heineken Cup.
It is by no means an easy draw for the Irish province, with Clermont Auvergne the Top 14 leaders going into the French league play-offs.
Montauban finished seventh in Top 14, and crept into qualification because Toulouse went further in last year’s competition than any English or Italian clubs.
Leinster must overcome Guinness Premiership champions London Wasps, along with Castres and Edinburgh making up Pool Two.
There is another imposing group for Ulster, with Stade Francais, Llanelli Scarlets and Harlequins awaiting them when the matches get under way in October.
Premiership runners-up Leicester were drawn against Perpignan, Welsh entertainers Ospreys and Italian minnows Treviso in Pool Three.
Defeated Heineken Cup finalists Toulouse are in Pool Five alongside Challenge Cup winners Bath, Newport Gwent Dragons and Glasgow.
In Pool Six, Gloucester appear to have a strong chance of qualifying from a group which also includes French side Biarritz, cup quarter-finalists Cardiff and Italy’s Calvisano.
Today’s draw was the first to use the new European Cup Rugby rankings system which split the clubs into four tiers based on performances in the competition over the last four seasons.