The Dominant II (introduced in 1976) had a deeper windscreen, rectangular headlights and a flat rear window.
The Dominant III had shallow, parallelogram-shaped side windows. The Dominant IV had conventional-shaped side windows, but shallower than those on the Dominant II.
The Duple Goldliner was a high-floor version of the Dominant III or IV.
The Duple Dominant E was a bus-specification version of the Dominant I or II. It is not to be confused with the visually dissimilar Dominant Bus which was available from 1974 to 1987.