The band's line-up took a while to stabilise, with, for example, Richard Sinclair depping for Clyne on their debut performance in January 1973; soon afterwards it settled on the quartet of Gowen, Travis, Phil Lee on guitar (recommended by Travis) and Neil Murray on bass. Regular gigs followed throughout 1973, including two special performances co-headlining with Hatfield and the North which included a "double-quartet" set consisting of a 40-minute composition by Gowen. A demo tape was also recorded for gig- and contract-hunting purposes.
In late 1973, Murray was replaced by Steve Cook but gigs subsequently became ever sparser, despite a series of radio sessions for the BBC's jazz programmes. For one of those the quartet were augmented with a second keyboard player, Peter Lemer. In 1975, Gilgamesh finally secured a contract with Virgin's subsidiary label Caroline Records, and recorded their debut album in downtime at the Virgin-owned Manor Studios, with Hatfield's Dave Stewart acting as co-producer.
Gowen and Stewart had become friends over the previous months and discussed a possible collaboration, but Stewart was hesitant about being in two bands simultaneously. When Hatfield and the North finally broke up in mid-1975, Stewart joined Gilgamesh as auxiliary member, playing one gig and a couple of radio sessions with the group. Meanwhile, plans were laid for the Stewart-Gowen collaboration, which eventually materialised as National Health and also (briefly) included Gilgamesh guitarist Phil Lee. Gilgamesh themselves ceased operations in late 1975 following the cancellation of a proposed Scottish tour.