Several months passed between the composition of Hyperion and its revision as The Fall of Hyperion. Keats began to write Hyperion in February 1818, only to discard it in frustration in April 1819; and it was not until July 1819 that he started to work on The Fall. During the period between the two poems, he revealed in a letter to his brother and sister-in-law in America that he was ‘reading lately two very different books Robertson's America and Voltaire's Siecle De Louis xiv’, an experience that he playfully describes as ‘like walking arm and arm between Pizarro and the great-little Monarch’ (LJK, II, 100). Keats's reading of the two histories in May 1819 occurred some weeks after he had abandoned Hyperion, but significantly, it was a rereading of texts already familiar to him from his schooldays and the period of his medical apprenticeship from 1810 to 1815; and following Hazlitt's endorsement of Gibbon and Voltaire in his 17 February 1818 lecture at the Surrey Institute, he had also previously read (or possibly even reread) Voltaire's Essai sur les mœurs and Gibbon's Decline and Fall (1776–88) as part of his preparation for Hyperion (LJK, I, 237).