The name Eloy is based on the H.G. Wells' book The Time Machine. In the book, Eloy is a human race from around 800,000 years in the future.
Early on, Bournemann was simply part of group making covers of popular music and in a decision to move away from this - Bournemann and his band changed their name to Eloy and began making their own kind of music. With their 2nd album, 1973's Inside, Eloy had firmly and unquestionably planted their musical direction into that of progressive rock.
By the release of Power and the Passion in 1975, the first symphonic concept album from the band it was apparent that Bornemann had found his direction while other members had different ideas. The band broke up (notably keyboardist Manfred Wieczorke moved on to the band Jane) allowing Bornemann to retain the band name and bring on other musicians who wanted to continue in this same direction.
For the next 3 albums, Eloy were clearly in their peak form as Dawn, Oceans and Silent Cries, Mighty Echos continued fimly in the direction started off by Power and the Passion and Eloy grew to become one of the biggest progressive rock bands in Germany.
Although more fine albums followed, there began a turnover in personnel and drifting in the band's style (beginning with the release of Colours) which ultimately resulting by 1988 in Eloy becomming essentially a duo of Bornemann and Michael Gerlach kicked off by the release of the album Ra.
By the later 1990's, many of the band's original musicians returned to the fold and the band began a renaissance of sorts - a highly successful 25th anniversary tour Eloy and the release of a number of albums in the mold of the classic Eloy sound.