The mushrooming success of league competitions in soccer in the late 1880's and early 1890's put increasing pressure on Rugby Union administrators to follow suit. In 1892, the Yorkshire County Rugby Union finally took the initiative and formed the Yorkshire Senior Competition. Bradford boasted two of the 10 founder members in  Bradford who played at Park Avenue and Manningham who were based at Valley Parade. The other eight were Batley, Brighouse Rangers, Dewsbury, Huddersfield, Hunslet, Liversedge, Halifax and Wakefield Trinity. The new competition was deemed a success as Bradford duly won the first title.

With high unemployment and long-running strikes, many players could not afford to play as amateurs and so were paid "under the counter". The Northern Unions tried to have broken time payments legalised in 1893, but were outvoted by the Southern establishment. Two years later the Yorkshire and Lancashire Senior Clubs tried to form a combined competition but were again rebuffed by the R.F.U.

In a move reminiscent of today's Super League, the Yorkshire elite rejected attempts by its county committee to impose a promotion and relegation system based on merit. This was the final straw that persuaded the senior Yorkshire and Lancashire clubs to go it alone. In August 1895, a meeting was called at the George Hotel in Huddersfield and a new breakaway Northern Football Union was formed.  Clubs in the N.F.U. would at last be able to pay their players, but for broken time only. Only Dewsbury stayed loyal to Rugby Union.

Bradford in fact turned to professional rugby very reluctantly. However large debts and the problems of organizing future amateur fixtures left the club with precious little choice. The break with Rugby Union was total and the breach between the two codes is now over 100 years old.

The Park Avenue-ites were successful in the new world of professional rugby and reached the 1898 Challenge Cup Final, before losing 7-0 to Batley at Leeds. The red, amber and blacks won the Yorkshire Senior Competition in 1899/00 and 1900/01. Star players included forward Jack Toothill, Welsh winger Fred Cooper, international forward Tom Broadley and Scots forward Alex Laidlaw.

The Yorkshire and Lancashire Senior Competitions combined to form the Northern Rugby League in 1901. After tying with Salford at the top of the new First Division in 1903/04, Bradford defeated the Lancastrians 5-0 at Thrum Hall in front of 12,000 spectators to become undisputed Rugby League champions.

The Bradford club also experimented with a new association section at Park Avenue in 1895 and its fortunes are chronicled in full for the first time in this website. However the round ball game struggled to compete with rugby and the section was finally closed down in 1899. 

However not everything in the Rugby League garden was rosy . In 1903, second division strugglers Manningham abandoned rugby league altogether and became Bradford City FC. Bradford soldiered on with the oval ball game and in 1906 won the Challenge Cup by defeating Salford 5-0 at Headingley.  The game was reduced from 15 to 13-a-side later that summer and the play-the-ball was introduced after a tackle.

Under the new rules things suddenly started to go downhill at Park Avenue. By late December, the club had slid to 24th place out of 27 and had lost £500 on the season. Gates were several thousand lower than those being enjoyed by Bradford City FC.  In desperation, the Bradford club applied for readmission to the Rugby Union which was granted in March 1907. This was accepted by the club's football section on 14th April, but the decision was later deemed "ultra vires" by the club's solicitor.

The Committee then changed its mind and decided that a change to association offered the best prospects. The switch was ratified at the club's AGM on 6th May 1907, boosted by the votes of many "guinea" or "social" members. A merger with Bradford City was seriously considered, but this plan was thankfully rejected by the Valley Parade membership. 

Having been rejected by the Football League, the new Bradford (Park Avenue) club joined the Southern League. Meanwhile Rugby League supporters reorganized themselves rapidly and on 24th May 1907 reformed under the name of Bradford Rugby F.C. As a goodwill gesture, Avenue passed all its old playing kit, footballs and goal posts to the new club. Worried that no one would realize that Northern Union was still being played within the city, the club extended its name to Bradford Northern R.F.C. in September 1907. The club made a new home for itself at Greenfield Athletic ground, the home of the very first Bradford City FC in 1901 and later to become a dog and speedway track.  Greenfield Stadium was demolished in the 1960's. Northern lost to Huddersfield in the opening match on 7th September watched by 7,000 spectators.

One Rugby League player surprisingly stayed loyal to the Park Avenue club despite the change of code. Joe Dunbavin took up the round ball game and made four appearances as an outside right in the Southern League.

Unhappy with facilities at Greenfield, Bradford Northern moved to Birch Lane in 1908, a ground that was used by the 1895-99 association section of Bradford FC when it was exiled from Park Avenue during its last season. Northern stayed at Birch Lane until 1934 when they moved to Odsal. The club went bankrupt in December 1963, but were back in membership of the Rugby League by August 1964. "If only it was so easy in football …" many Avenue fans must have wondered when the soccer side went bust in 1974. Northern changed their name to the Bradford Bulls in 1995 and, to this day, still refer to the events of 1907 as "The Great Betrayal".
 

This grainy old photograph of a Northern Union game at Park Avenue is taken from Trevor Delaney's book "The Grounds of Rugby League". The Low Stand survived until the ground was demolished in 1980.