This chapter provides an overview of histories of frozen earth while arguing that scholarship must attend to the historicity of permafrost as a scientific idea. It begins by discussing histories written before the establishment of permafrost science as a discipline. In this stage, terms for frozen earth had not yet been standardized, and interest in it was connected to major questions of nineteenth-century geology, especially the theory of ice ages. The chapter then considers histories written during the period of consolidating permafrost science, when state goals of colonization, industrialization, and militarization motivated research into frozen earth. Frozen earth became permafrost, and scientists used history to debate the discipline’s goals and orientation. Finally, the chapter analyzes histories written amid rising global awareness of anthropogenic climate change and the thawing of frozen earth. If, previously, histories of frozen earth were written primarily by scientists, in this stage scholars in the humanities and social sciences became increasingly engaged as well. They have explored the meanings of frozen earth in a variety of cultural contexts. This chapter argues that human engagements with frozen earth invested the phenomenon with multiple essences and names, of which permafrost was but one. While some conceptions of frozen earth recognized its inherent dynamism and heterogeneity, permafrost, a legacy of settler colonialism, suggested permanence and stability. Recovering alternative ways of understanding frozen earth can point to ways of living with change rather than maintaining expectations of stillness.