Centred on a Saxon-born Viking warrior in the 11th century, the strip mixed historical adventure with fantasy, and first appeared in the boys' anthology title Lion on 29 October 1960.

[1] He then pitched to Amalgamated Press, contributing odd strips to various titles before finding his niche on Tiger's "Olac the Gladiator", which established Lawrence as a historical action artist.

Lion editor Bernard Smith paired him with the experienced writer Ted Cowan, who had created Robot Archie for the title in 1952 among numerous other works for AP and Fleetway.

[4] Cowan meanwhile would hand over the reins to future novelist Michael Moorcock for the final arc of the strip; he and Lawrence would work together to devise "Maroc the Mighty", which would replace "Karl the Viking" in Lion from October 1964.

Audience research showed that readers typically only stayed with comics for three to five years while the low production quality of newsprint British weeklies meant issues were rarely saved or collected, and thus modified reprints were considered a valid cost-cutting exercise.

[14] Further threats included an airborne fungus possessed by the spirit Helvud;[15] Saracen hypnotist El Sarid;[16] Gefion One-Eye and his savage Skeld Vikings,[17] who mounted a challenge to Karl's leadership as they both fought the Kraken;[18] evil Moru the Sorcerer and his army, led by Elrik the Black;[19] Arabian tribe leader Talga[20] and numerous foes as the Vikings returned overland;[21] an African tribe led by the cruel Tava;[22] and a brutal rival Flamebeard.

[23] In an essay commissioned by Rebellion to celebrate the first Treasury of British Comics release, Doris V. Sutherland praised the series for its lavish artwork and imaginative world, a "carefree mash-up of different eras".

[3] Despite reservations about some of the dialogue, Karl Verhoven praised the collection for Slings & Arrows, feeling it charted Lawrence's development as an artist and that the "plots pack a lot in as they twist and turn".