In the last years of his life Leonardo wrote repeatedly at length about a cataclysmic storm overwhelming a landscape – his notes here run to almost 1000 words, with marginal illustrations of floods, a downpour, a whirlpool, and so on. This late obsession with destruction can be seen as the deeply personal expression of an artist nearing his end – an artist who had seen some of his greatest creations unfinished, decaying or destroyed, and who had a profound sense of the impermanence of all things, even of the earth itself.