Caul is a dark ambient project formed by Brett Smith, began in 1993, while he was playing guitar in John Bergin's band Trust Obey.

Brett Smith worked on material for about a year and in 1994 released the cassette Epiphany/Fortunate on his own label Epiphany Recordings. Two more releases followed, Whole and The Golden Section.
1996 saw both the first and second CD releases Crucible, courtesy of Malignant Records and The Sound of Faith, courtesy of Katyn Records. In 1997, Eibon released the third CD, Reliquary, and then in 1998 Caul returned home to Malignant Records for Light From Many Lamps.
There was a hiatus of about 3 years before the next Caul work, Hidden, was released by Eibon Records in 2001. The first installment in a 3 part work, the next installment, Muein, was released by John Bergin's Grinder label in 2002.

In 2002 Brett Smith resumed operations of his own label, Epiphany Recordings and in 2003 he released SWAN, a collection of compilation and unreleased recordings, followed by Eibon Records release of A Golden Epiphany, a remixed/remastered set of the very first Caul tapes.