German social historian Reinhart Koselleck theorizes modernity as an unprecedented expansion in the space of human experience and the horizon of human expectations. Koselleck’s decision to locate the break with the past in a “saddle time” (Sattelzeit), c. 1750–1850, stands in productive tension with the dominant medieval/modern periodization in English studies. Koselleck’s periodization aligns with those of Karl Marx, Michel Foucault, and a number of medieval literary scholars and historians who have challenged the historical centrality of the Renaissance. This essay redescribes Koselleck’s theorization of the simultaneity of the nonsimultaneous (Gleichzeitigkeit des Ungleichzeitigen) as an alternative strategy for holding the strangeness of period in mind, a strategy Koselleck himself did not pursue to its logical conclusion. Consideration of the “already” secular early English literary genre of political prophecy, to which Koselleck alludes in the opening chapter of his book Futures Past, elucidates the structures of thought that Koselleck regards as modern within the centuries that Koselleck excludes from modernity.