Up to 30 rival bikers fought a mass brawl inside a terminal building at Birmingham International Airport armed with knives, a machete and other weapons, a court heard.
A jury sitting at Birmingham Crown Court was told the "battle", which left on-lookers at the city's airport frightened and distressed, involved members of the Hell's Angels and the Outlaws, some of whom had arrived on a flight from Spain.
Opening the case against 12 men charged with riot and an alternative count of violent disorder, prosecutor Timothy Raggatt QC revealed that a club, knuckle-dusters, three hammers and a meat cleaver were recovered after the violence on the evening of January 20 last year.
Mr Raggatt told the jury: "It's the prosecution case - and common knowledge - that the two groups are groups who have a long-standing rivalry.
"In the course of what happened, a variety of in some cases quite alarming weapons were used - there were knives produced, there was certainly a machete produced and there were various blunt instruments."
Mr Raggatt added that a number of those involved in the violence were injured, although no innocent members of the public were hurt.
Those who witnessed the clashes were profoundly alarmed and distressed by what they had seen, Mr Raggatt said, adding: "This was a piece of serious, very frightening public disorder involving two groups of people who were both quite obviously prepared to fight each other."
The jury heard that seven of the men in the dock were members of the Outlaws, while the other five were known to be Hell's Angels.
Before the court are Mark Larner, 47; Maurice Ison, 51; Paul Arlett, 35; Kevin Timmins, 28; Robert Haywood, 46; Mark Price, 50; Sean Timmins, 38; Leonard Hawthorne, 52; Mark Moseley, 45; Jeremy Ball, 46; Marc Wilden, 44, and 46-year-old Neale Harrison.
Larner, from Upper Gornal, West Midlands; Arlett, of Cradley Heath, West Midlands; Wilden, from Coventry; Kevin Timmins, of Sedgley, West Midlands; Price, of Nuneaton, Warwickshire; Sean Timmins, of Coven, Staffordshire; Hawthorne, from Wolverhampton; Moseley, from Yardley, Birmingham; Harrison, of Bell Green, Coventry; and Ison, Ball and Haywood, whose addresses have been withheld by the court, all deny riot and violent disorder.