As the name "Annus Mirabilis" implies, the poem is about a year of miracles. Dryden writes this poem to commemorate the events of the year 1666 in England. He begins with a focus on the conflicts between the Dutch and the English. Their navies were at war with one another, until France fatefully intervened in favor of the British to decide the matter. These countries continued to maintain their rivalry for years, however, as the Dutch refused to allow Britain naval superiority. Eventually, however, they must cede to the English their due as the dominant global naval superpower.
Dryden then turns to the homeland. Dealing with the loss of many of their beloved husbands and fathers at sea, the people are in mourning. Then the plague breaks out. People move the country to try to avoid the plague's destructive swiftness, but only the truly wealthy are able to afford the resources to escape fast enough. The rulers of the day are unable to aid the people because they are so concerned with their petty rivalries with neighboring countries. In fact, so many die that the nation is torn in pieces as its population dwindles.
Then the fire occurs in London. Dryden devotes lines and lines to chronicling the fire's destructiveness. It burns the majority of the city, from the center and the Tower of London all the way to the Thames. Finally, the king orders buildings in the center of town to be torn down to prevent further spread and the entire destruction of the city. The true tragedy of the affair is that the portion of the population which is devastated by the fire is mainly the poor because their houses are made of highly flammable materials and packed insufferably close together. Still, thanks to the king's foresight, the rest of the city is spared what would have been a national crisis if it had too gone up in flames.