Historical allusion is a reference, usually within a speech or a piece of writing, to people or events that have historical significance and carry certain ideas along with them. Someone in the US, for example, might refer to a person as a “Benedict Arnold,” which is a reference to the American general that joined British forces during the Revolutionary War. Using this allusion to refer to someone can quickly and succinctly, for American audiences at least, indicate that someone is a traitor or “turn coat.” Historical allusion can be used in works of literature to refer to events or people in a way that makes the events or characters of a work more relatable.
An allusion in general, not to be confused with an “illusion,” is a reference to something within a particular context, often a speech or written text. The use of an allusion, such as a historical allusion, acts as a literary or rhetorical device that allows the work to more easily connect with a reader or listener. Allusions are often based on the context or audience of a particular work and may be wasted on an audience that does not understand a particular reference. An historical allusion to events that happened in ancient Chinese history, for example, is likely to be missed by most readers in the US.
This means that the effectiveness of an historical allusion often depends on the writer or speaker understanding his or her audience. The use of “Benedict Arnold” is fairly cultural, and while people in the US are likely to understand it, Europeans may miss or not fully understand the reference. There are somewhat more general allusions that can be made, however, often by referring to larger events that have global awareness. The term “Waterloo” is often used as an historical allusion to the Battle of Waterloo that saw the final defeat of Napoleon Bonaparte, and this reference is likely to be understood by a wide range of Western audiences in the US, Canada, and throughout much of Europe.
A writer can often use an historical allusion to make connections between different ideas, or to allow a reader to better understand a potentially complex idea. Someone writing a scene depicting a battle in a science fiction setting, such as a war between alien cultures on a faraway world, might use such an allusion to more fully connect with a reader. Descriptions of deep trenches and poisonous gas clouds filling the air would likely act as an historical allusion to the battlefields of World War I, which would allow the scene to connect with a reader and make it feel more realistic and relatable. Politicians and other public speakers often use historical allusions to evoke feelings or images in the minds of listeners, frequently to appeal to patriotic or nostalgic ideologies.