Celtic Crusaders were founded in 2005 and first entered National League Two in 2006.
The club was formed following a number of years of successful development work at amateur level in Wales. A season of professional rugby league was played in the area in 1996 with South Wales who finished sixth in Division Two. After this club was wound up, rugby league continued with the introduction of Cardiff Demons the following year who played four seasons in the Senior Academy alongside teams from professional northern clubs.
The Demons reached the Grand Final of the Academy Division Two in their second season but lost to Hunslet Hawks. They also had a successful Challenge Cup run in 1999-2000 where they knocked out Durham and Rochdale Mayfield before losing to Keighley Cougars.
The club then transferred to the Rugby League Conference and their continued success inspired other clubs from around Wales to form. Bridgend Blue Bulls were the most successful of these. Since they were founded in 2003, they have won every Welsh title and two National Conference crowns. Celtic Crusaders was the next natural step following all of this success.
The philosophy behind the creation of the Crusaders was a bottom up approach to ensure that the club grew with its playing and spectator base, into a nationally recognised sporting brand. The Crusaders' first match took place against Harlequins Academy at Brewery Field in January 2006, the club used the fixture as a chance to view the fringe players in their squad and secured a 22-22 draw. Their first competitive games were in the National League Cup - Crusaders were placed in a group along with London Skolars, Hemel Stags and St Albans Centurions, won every game convincingly and were installed as favourites to win National League Two in their first year. However, the team finished a creditable third and lost out 26-27 in the Final Eliminator to Swinton Lions.
In only their second season of existence, the Celtic Crusaders won the 2007 National League Two championship, thus earning automatic promotion to National League One in 2008. The title was sealed with one match left to play as a result of Featherstone Rovers away loss at Barrow Raiders on September 8, 2007. In that year fullback Tony Duggan won the National League Two Player of the Year award for 2007 with 40 tries through 2007.Jace Van Dijk, Neale Wyatt, Damien Quinn, Mark Dalle Cort, Neil Budworth, all joined Duggan in the National League Two all-star team.
In their first ever Co-operative National League One match, Celtic Crusaders, in atrocious conditions, claimed a hard-fought 14-12 win over Dewsbury Rams. Against the odds, they ended up finishing second in National League One and were also runners up in the Grand Final.
Much of the first team squad are Welsh-qualified having been recruited from Welsh Conference, Super League and National League clubs. The club also runs an academy side drawn from every club in the Welsh Conference.
The club run under 18 and under 16 sides and in their first year, the under 18s won the Gillette National Youth League after beating the favourites Leigh Miners Rangers 32-0 in the Final in April 2009.
The Crusaders have been getting healthy crowds since inception. Their highest ever attendance in National League 2 was on Friday May 4, 2007 when 3,441 people witnessed them play Oldham Roughyeds at the Brewery Field. This attendance was also an NL2 record attendance and the first NL2 match broadcast live on British television. In 2008, a crowd of 6,152 attended the National League One game against Featherstone Rovers on Friday May 3 while in 2009 a new record of 6,351 attended the engage Super League match against St Helens.
In 2008 Celtic Crusaders signalled their ambition for Super League rugby and were one of 19 clubs to submit an application for a Super League licence. They were accepted and started playing in Super League in 2009.