Dublin City Council has ruled that the historic Smithfield horse fair will now take place just twice a year, rather than the current monthly event.
The fairs will be held on the first Sunday of March and September, between 09.30 and 13.30, while extra fair days during the summer may be added at a future date.
By-laws govern animal welfare as well as safety and parking and there is a strict ban on dogs.
Horse owners will only be permitted to sell horses if in possession of a casual trading licence issued by Dublin City Council, a valid equine passport and public liability insurance for the display or selling of a horse in a public place.
Traders may not ride the horses at the fair but the animals can be trotted in the square if led by hand. Horses must be kept under control at all times and be provided with sufficient food and water. There is also a ban on bringing "unfit" horses to the fair whose site is located in the north inner city, near the Luas tramline.
Used as a horse market since the mid-17th century, its ancient trading rights prohibit Dublin City Council from closing it down, something they have sought to do for over a decade. It was temporarily banned in 2002 after a horse bolted and collided with an occupied car on the quays but the traders soon returned claiming it was their right.
The controversial fair has regularly been the scene of anti-social behaviour, most recently in 2011 when men attacked each other with machetes and home-made guns, leading to a mass brawl.