His future musical partner, Krust, had been a member of the Fresh 4, whose “Wishing on a Star” reached the Top 10 of the UK Singles Chart in late 1989. Williams, Krust, Suv and DJ Die founded Full Cycle Records.

Aided by Chris Lewis, Roni Size founded the record label WTP (“Where’s The Party At?”) as part of Circus Warp. With Dave Cridge who also DJed for Circus Warp and ran Replay Records Bristol, the two would visit The Record Basement in Reading and in 1993, Full Cycle and Dope Dragon were established. RCA Records employee Bryan Gee was an early admirer. In 1994, when he founded V Recordings, the first releases were Krust’s Deceivers EP as catalogue number V001 and Agility, the debut release of Roni Size and DJ Die, as V002. In 1997, Roni Size and Reprazent released their biggest single in Southeast Asia, specifically in the Philippines, with “Brown Paper Bag”.

Williams subsequently teamed up with DJ Die and Leonie Laws in Breakbeat Era, before returning to Reprazent to record the second album, October 2000’s In the Mode, which included guest vocals from Zack de la Rocha of Rage Against the Machine and Method Man of Wu-Tang Clan. In 2001, he returned to the studio and started working with Tali, who had recently arrived from New Zealand on her album Lyric on My Lip. In this time, he also produced Touching Down – released in October 2002. This, his first truly solo album, included 16 tracks segued into one hour’s set. He came back to V Recordings in 2005 with the release of Return To V, which included vocal collaborations with artists such as Beverly Knight, Jocelyn Brown, Vikter Duplaix and Rodney P.

Roni Size resurrected Reprazent in 2008 with the release of a deluxe edition of New Forms on Universal. The reformed band included original members Dynamite MC, Onallee and bass player Si John alongside Yuval Gabay (Soul Coughing), D Product, Jay Wilcox and Pete Josef. Roni Size and Reprazent toured in some of the biggest festivals in Europe, including Bestival, Glastonbury, Lovebox (festival), EXIT and Rock Herk. As a result, they were among the nominees for Best Dance Act from the UK Festival Awards.

In September 2009, Roni Size and Reprazent played a gig with an orchestra and choir to mark the re-opening of Bristol’s Colston Hall, collaborating with the BBC’s Nature’s Great Events composer, William Goodchild. In addition to older material, the band played material from a forthcoming Reprazent album.