The United Rugby Championship was launched in 2001 as a collaboration of the Irish, Welsh and Scottish leagues, known as the Celtic League.
The first year of the Celtic League saw 15 teams compete, the four Irish provinces, two Scottish teams and all nine professional Welsh sides.
That number dropped in 2003 as the WRU decided to form five official professional Welsh sides, dropping the league's total down to 12, with an extra Scottish team.
In 2010, the biggest change yet struck the competition, with two Italian teams replacing a Scottish and a Welsh side in the league, just one year before it rebranded to the Pro 12.
The league continued in the same structure until controversially, in 2017, two South African teams joined the competition, bringing the total teams up to 14 and causing a rebrand to the Pro 14.
With the increase in numbers, the structure became two separate leagues, or a 'conference structure', which would see the sides face all of the teams in their respective conference twice and the other sides once.
An official rebrand to the United Rugby Championship (URC) came in 2021, with 16 teams now in the competition - due to an increase in the South African contingent - and teams split into pools of their own nation.
Under the new format, teams play six matches against their regional pool rivals. The remaining matches are made up by an even number of six home and six away matches against all the remaining sides in the competition.
Since their introduction - despite having only won one title so far - the South African sides have performed extremely well, with one of their sides reaching the final in each of the last five seasons.
Read the full list of winners below.
United Rugby Championship previous winners
Celtic League
Season | Champions | Runners-up | Grand Final result * |
2001/02 | Leinster | Munster | 24-20 |
2002/03 | Munster | Neath | 37-17 |
2003/04 | Scarlets | Ulster | N/A |
2004/05 | Ospreys | Munster | N/A |
2005/06 | Ulster | Leinster | N/A |
2006/07 | Ospreys | Cardiff Blues | N/A |
2007/08 | Leinster | Cardiff Blues | N/A |
2008/09 | Munster | Edinburgh | N/A |
2009/10 | Ospreys | Leinster | 17-12 |
2010/11 | Munster | Leinster | 19-9 |
*Between 2003 and 2009, there were no play-offs or Grand Final, with the team finishing top of the table crowned champions.
Pro 12
Season | Champions | Runners-up | Grand Final result |
2011/12 | Ospreys | Leinster | 31-30 |
2012/13 | Leinster | Ulster | 24-18 |
2013/14 | Leinster | Glasgow | 34-12 |
2014/15 | Glasgow | Munster | 31-13 |
2015/16 | Connaght | Leinster | 20-10 |
2016/17 | Scarlets | Munster | 46-22 |
Pro 14
Season | Champions | Runners-up | Grand Final result |
2017/18 | Leinster | Scarlets | 40-32 |
2018/19 | Leinster | Glasgow | 18-15 |
2019/20 | Leinster | Ulster | 27-5 |
2020/21 | Leinster | Munster | 16-6 |
United Rugby Championship
Season | Champions | Runners-up | Grand Final result |
2021/22 | Stormers | Bulls | 18-12 |
2022/23 | Munster | Stormers | 19-14 |
2023/24 | Glasgow | Bulls | 21-16 |
2024/25 | Leinster | Bulls | 32-7 |
2025/26 | Leinster | Bulls | 36-7 |
United Rugby Championship Winners
Leinster | 10 |
Ospreys & Munster | 4 |
Scarlets & Glasgow | 2 |
Connacht, Ulster & Stormers | 1 |
