what is the henley cup?
Henley Royal Regatta. Henley Royal Regatta, annual four-day series of rowing races held the first week in July on the River Thames, at Henley-on-Thames, Oxfordshire, Eng. The regatta was established in 1839; and in 1851 Prince Albert became its patron and gave the event its âroyalâ prefix. The regulation distance for the races is 1 mile 550 yards (2,100 m).