More than 50 people have been arrested at the Appleby Horse Fair in Cumbria - more than half of whom were involved in mass brawl.
The week-long event, which began on Thursday, attracts about 10,000 Gypsies and travellers and 30,000 visitors.
Cumbria Police had their busiest night of the fair so far on Saturday, with 53 arrests - 27 of which were linked to a disturbance among a group of men.
On Friday, fake goods with a street value of £250,000 were recovered.
Ch Supt Steve Johnson said: "Our officers are working hard to provide proportionate enforcement of the law.
"Saturday nights are always the busiest of the event, but we dealt with issues quickly and successfully with minimal disruption to the local community."
One man was taken to hospital with head injuries after the fight. The 27 men were arrested on suspicion of violent disorder.
Other arrests were linked to alcohol and drugs offences.