This game was created by Lewis Pulsipher in 1983 under the working title of "Invasions". It was first published by Gibsons Games as "Britannia" from 1986 in the United Kingdom in two slightly different versions after development by Roger Heyworth. A German-language version was released by Welt der Spiele and the game was later republished in the United States by Avalon Hill. The game developed a devoted following across the world, generating variants and additions. One of the most popular additions was the 'Oh Danny Boy' By Jim Lawler, which included a variant for the First Edition rules. The rules included Isle of Man (part of England) and 4 Irish areas, an extra leader 'Brian Boru' was also an option.