Rugby football stems from the form of the game played at Rugby School, which former pupils then introduced to their universities.

Former Rugby School student Albert Pell is credited with having formed the first “football” team while a student at Cambridge University. Major private schools each used different rules during this early period, with former pupils from Rugby and Eton attempting to carry their preferred rules through to their universities.
A significant event in the early development of rugby football was the production of a written set of rules at Rugby School in 1845, followed by the Cambridge Rules that were drawn up in 1848.

Formed in 1863, the national governing body The Football Association (FA) began codifying a set of universal football rules. These new rules specifically banned players from running with the ball in hand and also disallowed hacking (kicking players in the shins), both of which were legal and common tactics under the Rugby School’s rules of the sport. In protest at the imposition of the new rules, the Blackheath Club left the FA followed by several other clubs that also favored the “Rugby Rules”. Although these clubs decided to ban hacking soon afterwards, the split was permanent, and the FA’s codified rules became known as “association football” whilst the clubs that had favored the Rugby Rules formed the Rugby Football Union in 1871, and their code became known as “rugby football”.

On 4 December 1870, Edwin Ash of Richmond and Benjamin Burns of Blackheath published a letter in The Times suggesting that “those who play the rugby-type game should meet to form a code of practice as various clubs play to rules which differ from others, which makes the game difficult to play”. On 26 January 1871, a meeting attended by representatives from 21 clubs was held in London at the Pall Mall restaurant.

Alterations to the laws of rugby union were trialled by students of Stellenbosch University in South Africa in 2006, and were adopted in competitions in Scotland and Australia since 2007, though only a few of the rules were universally adopted. The law variations are an attempt to make rugby union easier to understand by referees, fans and players, but the laws were controversial and far from being endorsed by all members of these groups.[72] After a number of trials around half of the proposed changes were permanently added to the laws of the sport.

In 2012, the Tri Nations was expanded to include Argentina, with the competition being renamed The Rugby Championship. The competition’s organiser, now known as SANZAAR after the Argentine Rugby Union became a full member in 2016, has also expanded Super Rugby in the 21st century, first expanding from 12 to 14 teams in 2006, then to 15 teams in 2011, and most recently to 18 teams in 2016. The last of these expansions spread Super Rugby’s geographic scope outside of its founding countries (South Africa, Australia, New Zealand) for the first time, adding new teams in Argentina and Japan.

In 2014, the European club competition structure was revamped. The top-level Heineken Cup and second-level European Challenge Cup were respectively replaced by the European Rugby Champions Cup and European Rugby Challenge Cup.

The most significant changes to the structure were a reduction in the number of clubs taking part in the top competition from 24 to 20, plus the introduction of a play-off to determine one place in the Champions Cup.
Following several years of tension within the SANZAAR consortium and knock-on effects from COVID-19, the 2020s saw major changes to the structure of international club rugby. Super Rugby lost its Japanese side even before COVID-19, and its Argentine side withdrew in 2020. More significantly, South Africa pivoted away from SANZAAR and aligned its club structure with that of Europe. Two South African sides had joined the competition previously known as Pro12 after that league’s 2016–17 season, though the country’s major regional sides remained in Super Rugby. One of the two Pro14 clubs folded before the 2020–21 season, and the other left the competition at the end of that season. South Africa’s four major regional sides then left Super Rugby to join Pro14, which was duly renamed the United Rugby Championship, starting in 2021–22. South Africa’s URC clubs became fully integrated with the European club system effective with the 2022–23 northern hemisphere season.

As for Super Rugby, it would be rebranded as Super Rugby Pacific in 2022, featuring five teams each from Australia and New Zealand, plus one representing Fiji and another nominally representing the Pacific islands as a whole (but mainly Samoa and Tonga).