European Champions Cup: Saracens begin defence at Northampton Saints
Saracens will begin their defence of the European Champions Cup at Northampton Saints on 15 October.
Sarries, who beat Clermont in last season's final, are aiming to become only the second club to win three consecutive titles.
Premiership champions Exeter host Glasgow, while Wales full-back Leigh Halfpenny faces former side Toulon, who host Pro12 champions Scarlets.
The opening round of pool matches take place from 13-15 October.
Leicester are at Racing 92, Ulster host Wasps, Harlequins entertain La Rochelle, Bath host Benetton Treviso, Leinster meet Montpellier and Munster travel to Castres.
In the European Challenge Cup, holders Stade Francais will open their defence with a trip to tournament newcomers Krasny Yar of Russia on 14 October.
Switzerland will stage a match when Oyonnax meet Connacht at the Stade de Geneve on the same day.
Gloucester travel to Pau, Cardiff Blues host Lyon, Sale Sharks entertain Toulouse, Newcastle host the Dragons, London Irish face Edinburgh and Worcester play Brive.
The Challenge Cup and Champions Cup finals will be held at Bilbao's San Mames Stadium on 11 and 12 May 2018 respectively.
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