A leaflet published in 1631 contained the phrase "nach dem Aprill schicket" in its title. This is the earliest known appearance in print of the phrase "in den April schicken" (or a variant thereof), this being a German idiom meaning to make an April Fool of someone (literally, "to send someone in April").
The leaflet was titled "Eigentliche Contrafactur, Wie Kön. May. zu Schweden den alten Corporal Tyllen nach dem Aprill schicket"
It mocked Count Tilly, commander of the Catholic League's forces during the Thirty Years' War, as an April Fool after he was defeated by the King of Sweden.