Originally a pseudonym for solo recordings by Steven Wilson, Colin Edwin, Chris Maitland & Richard Barbieri joined the band in 1993 and the band stayed that way until 2002, when Chris Maitland left the group, and Gavin Harrison replaced him.
Since their last album "The Incident", the band has not officially disbanded, as many would like to think.
Steven Wilson has stated that Porcupine Tree will never be his prime focus again but only a side project. But he is open for more material in the future should the opportunities present itself.
Reason for this is because PT never let him explore beyond the core genre of the band like his solo work would allow him to do.