First published in English in 2007 under title: The history of terrorism: from antiquity to al Qaeda.

"My aim in it has been to convey a juster and less prejudiced notion than prevails at present respecting the Danish and Norwegian conquests." -Jens Jacob Asmussen Worsaae, An Account of the Danes and the Norwegians (1852) An Account of the Danes and the Norwegians in England, Scotland and Ireland (1852) by Jens Warsaae, was based on his research into the Scandinavian invasions of the European mainland. During the 10th century, the European mainland was invaded by Norse settlers from Denmark, Norway, and Sweden, who intermarried with native tribes and came to be known as "Normans." While their influence on the history of France was significant, it was even stronger in England, which the Normans conquered in the 11th century. Warsaae's book, commissioned by the Royal Society of Northern Antiquaries, was his attempt to revise the impressions that the 19th century British had of the effects of the Norman conquests on England. This replica of the original text is accompanied by numerous woodcuts.

Gibbon offers an explanation for why the Roman Empire fell, a task made difficult by a lack of comprehensive written sources, though he was not the only historian to tackle the subject. Most of his ideas are directly taken from what few relevant records were available: those of the Roman moralists of the 4th and 5th centuries.