The picture at left is a caricature by Thomas Rowlandson from November 1807 showing John Bull (representing England) looking on as a comet-entrained Napoleon ascends from the shore of France toward King George III. Bright 18th and 19th-century comets often appeared in such satirical commentary.
It’s certainly been a while since a truly “great” comet has been visible in the sky. Some 20 years ago there were clos-spaced appearances of comets in 1996-1997 but they required magnification to pick out, and owing to light polluted skies, they were all the more difficult to catch sight of.
If we go back 200 years to the Napoleonic era of the early 19th century, we have two “great comets” that appeared four years apart. This was a time of great conflict. Napoleon’s armies held sway over much of Western Europe, while England’s fleet blockaded the Continent. Yet despite the widespread devastation and political chaos, astronomy flourished under Napoleon’s new World Order.
Both of the “Napoleonic comets” had an impact on everyday society—even though astronomers of the time knew they were merely celestial objects. The Great Comet of 1811 was seen as a portent of the upcoming war against Russia, while Napoleon took its appearance a step further and used it as a sign of impending victory. Without doubt, its continued presence in the sky inspired a dramatic rise in “comet art,” as British political artists and writers had fun mocking the Emperor’s connections to comets. Tolstoy’s War and Peace makes mention of this comet, and there was even an exceptional French vintage of 1811 “comet wine.”
Although the 20-years-ago Hale-Bopp comet (18-month run) shattered the naked-eye visibility records established by the visitors in 1807 and 1811, the latter certainly left their mark on history. So when will there be another close paring of Great Comets crossing the sky? Only time will tell—but their passing will no doubt be equally memorable.
The Great Comet of 1811 was impressive. H. R. Cook did an engraving of the Great Comet as it appeared at daybreak on October 15th of that year from near Winchester, England.
 See Rich Jakiel, “Napoleon’s Comets,” Sky and Telescope (133, 5, May, 2017, pp. 52-53)