Ludmilla Assing, the niece of Varnhagen von Ense, was the editor of this selection of letters from Alexander von Humboldt to her uncle – to who Humboldt had entrusted the preservation of their correspondence – in the period 1827–58. First published in 1860, Letters of Alexander von Humboldt also contains letters from Varnhagen and other distinguished correspondents to Humboldt. Some passages from Varnhagen's diary are also included to supply a vivid commentary on the letters, which present detailed records of Humboldt's life, activity, and habits of thought, and contain materials of unquestionable importance for portraying an accurate picture of his mind and character. The other letters contained in the volume illustrate his worldwide circle of correspondents. This collection was published after the deaths of both Varnhagen and Humboldt. Explanatory notes and a full index of names accompany this authorised translation from the original German.