1989–2000: four-piece band, Anam, Banba, and Lore
In 1989, Pól Brennan left Clannad to work with Peter Gabriel as a producer for the WOMAD arts festival and as an acoustic specialist. The band continued as a four-piece and wrote, arranged, and recorded their next album, Anam ('Soul'), in under three months, with Ciarán Brennan becoming their producer and primary songwriter. Released in October 1990, the album – which included the group's sister/niece Brídín Brennan as a guest harmony vocalist – peaked at No. 14 in the UK. Its US release followed in 1992 and included "In a Lifetime" and "Theme from Harry's Game", which had appeared in the film Patriot Games (1992) and a Volkswagen television advert, boosting the group's recognition. The interest generated by the Volkswagen advert saw Anam reach No. 46 on the US Billboard 200, the group's highest position on the chart. In 1996, the album reached gold certification in the US after selling 500,000 copies. The track won a Billboard Music Award for World Music Song of the Year. "Rí na Cruinne" was included on One World One Voice, a charity compilation album intended to raise awareness of environmental issues.
In 1990, Brídín re-joined the group for live performances, supplying additional instruments and backing vocals. Around this time a documentary on the band's 20-year history was produced, titled Clannad in Donegal. In 1991, Clannad released a cover version of "Both Sides Now" by Joni Mitchell, as a duet with singer Paul Young. The track had been recorded for the Blake Edwards film Switch.
In late 1992, the group started working on material for their next album, Banba, named after an Irish mythological figure. Ciarán wrote fifteen songs in his home studio, and he and Máire picked out tracks to develop further and produced demos, then arranged the best parts into complete songs. Released in May 1993, the album went to No. 5 in the UK and No. 110 in the US. It featured "I Will Find You", written for the film The Last of the Mohicans (1992), and had Máire singing in English, Mohican, and Cherokee. Máire said director Michael Mann had liked their Irish songs, but they were unsure of writing a song about early American history in Irish and opted instead to use Native American languages. An English version was also recorded. Banba was nominated for a Grammy Award for Best New Age Album and, like its predecessor, it achieved gold certification in the US after selling 500,000 copies. The album was supported by Clannad's 20th anniversary UK tour, which ended in July 1993 with a concert at Lincoln Castle.
By early 1996, Clannad had recorded and finished the next album, Lore, but its release was delayed after the band tried to leave BMG (owner of RCA Records since 1987) and sign a worldwide deal with Atlantic Records, their US distributor. Released in March 1996, the album, which featured American drummer Vinnie Colaiuta, reached No. 14 in the UK and debuted at No. 1 on the Billboard Top World Albums chart, displacing Gipsy Kings after their 24-week run at the top. "Croí Cróga" ('Brave Heart') was originally written for the Mel Gibson film Braveheart (1995), but did not make the final cut for its soundtrack. "Farewell Love" was used in the soundtrack of the Irish drama film A Further Gesture (1997).
Clannad's tour to promote the album included their first sold-out shows in Japan, and also featured another of the younger siblings, Deirdre (Dee) Brennan, as a touring member of the band on bodhrán percussion and backing vocals (along with guest musicians Mel Collins, Ian Parker, Ian Melrose, and Ray Fean, several of whom would collaborate on further Clannad and Máire/Moya Brennan albums).
Also that year, Clannad received a Lifetime Achievement Award from the Irish Recorded Music Association. In April 1996, the group split with their manager, Dave Kavanagh, after 14 years.
Clannad returned to RCA/BMG in 1997 with the album Landmarks. Deirdre Brennan reappeared as guest bodhrán player on two tracks, "Let Me See" and "Of This Land"; in the latter, Máire sang about Ireland's past and future. The track "Fadó" ('Long Ago') demonstrated the influences of Celtic history on the band's music. In 1999, Landmarks won the group a Grammy award for Best New Age Album. Also in 1999, the group wrote "What Will I Do" for the Kevin Costner romantic-drama film Message in a Bottle.