After he agrees, Mordrin uses mind-altering drugs to place the post-hypnotic suggestion in Gervase's mind that he should seek out and destroy the Prior's "greatest enemy."

Unknown to Gervase, Mordrin needs Julia alive as well, as she is the daughter of Brigadier Clarke, the senior officer in the Coldstream Guards, the last remnant of the British Army, which has been allowed to survive for ceremonial purposes, all other units having been absorbed into the Knights.

These differences and other details – such as that the Knights wear black but otherwise conventional battledress – suggest that the book was written before production and that the television script was therefore expanded to fit the desired length.

The novel also contains much additional detail about the world of 2020 and the Civil War, such as Ireland as a whole having become an American state, and the source of much of the rebels' supplies, despite an official arms embargo.

It is mentioned that whilst Hugo uses his position to secure personal luxuries, and especially alcohol, Mordrin is a teetotal vegetarian, with hints that he suffers from obsessive compulsive disorder.

The TV Times reported Don Henderson's appearance in the serial in its edition of 14–20 September 1985, accompanied by a photograph of the actor as his character in the programme, stating: "Filmed in Hampshire and North Wales, this vision of a bleak future is set in the year 2020 after Britain has been devastated by civil war."

The serial was shown in France by Canal Plus from 7 October to 30 December 1987, under the title Les Épées de feu ("The Swords of Fire"), and subsequently repeated on La Cinq and FR3.

A single-tape German-dubbed 199 minute compilation was released on VHS in Switzerland as 2019 – Die Gnadenlosen Knechte Gottes ("2019 – The Merciless Warriors of God"); it was re-released as a limited edition DVD in Austria in 2020.

A single-tape dubbed 148 minute version was released in Spain as Los Caballeros De Dios – Año 2020 (The Knights of God – Year 2020).

This is probably due to ongoing complex rights issues after the production company, TVS, lost its ITV franchise in 1992 and subsequently went through a number of take-overs.

This problem affects the majority of the TVS programme archive, since much of the original production paperwork and sales documentation has been lost during the intervening years.