The Irish, Scottish and Welsh Rugby Unions have unveiled their Celtic Accord for the new-look Celtic League.
The Accord ratifies the decision of the three Unions to start the Celtic League this year.
The agreement, which was finally reached yesterday, confirms that four Irish provinces, two Scottish professional teams and nine Welsh clubs have committed to the competition, which kicks off on the weekend of Saturday 18 August with the final on Saturday 15 December.
The competition will be played in two conferences before the knockout stages.
"I am convinced the Celtic League can only be good for the rugby development of our three countries and that, in turn, can only be beneficial for the overall strength of Northern Hemisphere rugby," said Syd Millar, who chaired the group.
The fixture list was agreed at yesterday's meeting and will be released after consultation with relevant commercial bodies with an announcement on sponsorship to follow.
The new-look Celtic League will run for an initial period of three years.
Teams involved in the first year are:
Ireland
Connacht
Leinster
Munster
Ulster
Scotland
Edinburgh Reivers
Glasgow Caledonians
Wales
Bridgend
Caerphilly
Cardiff
Ebbw Vale
Llanelli
Neath
Newport
Pontypridd
Swansea
PA