He immediately set to work on his _French Revolution_. While it was in progress he in 1835 lent the MS. to J.S. Mill, by whose servant nearly the whole of the first vol. was burned, in spite of which misfortune the work was ready for publication in 1837. Its originality, brilliance, and vividness took the world by storm, and his reputation as one of the foremost men of letters in the country was at once and finally established. In the same year he appeared as a public lecturer, and delivered four courses on _German Literature_, _Periods of European Culture_, _Revolutions of Modern Europe_, and _Heroes and Hero-Worship_, the last of which was _pub._ as a book in 1841. Although his writings did not yet produce a large income, his circumstances had become comfortable, owing to Mrs. C. having succeeded to her patrimony in 1840. Books now followed each other rapidly, _Chartism_ had appeared in 1839, _Past and Present_ came out in 1843, and _Letters and Speeches of Oliver Cromwell_ in 1845, the last named being perhaps the most successful of his writings, inasmuch as it fully attained the object aimed at in clearing Cromwell from the ignorant or malevolent aspersions under which he had long lain, and giving him his just place among the greatest of the nation. In 1850 he _pub._ his fiercest blast, _Latter Day Pamphlets_, which was followed next year by his biography of his friend John Sterling (_q.v._). It was about this time, as is shown by the _Letters and Memoirs_ of Mrs. C., that a temporary estrangement arose between his wife and himself, based apparently on Mrs. C.'s part upon his friendship with Lady Ashburton, a cause of which C. seems to have been unconscious. In 1851 he began his largest, if not his greatest work, _Frederick the Great_, which occupied him from that year until 1865, and in connection with which he made two visits to Germany in 1852 and 1858. It is a work of astonishing research and abounds in brilliant passages, but lacks the concentrated intensity of _The French Revolution_. It is, however, the one of his works which enjoys the highest reputation in Germany. In 1865 he was elected Lord Rector of the Univ. of Edin., and delivered a remarkable address to the students by whom he was received with enthusiasm. Almost immediately afterwards a heavy blow fell upon him in the death of Mrs. C., and in the discovery, from her diary, of how greatly she had suffered, unknown to him, from the neglect and want of consideration which, owing to absorption in his work and other causes, he had perhaps unconsciously shown. Whatever his faults, of which the most was made in some quarters, there can be no doubt that C. and his wife were sincerely attached to each other, and that he deeply mourned her. In 1866 his _Reminiscences_ (_pub._ 1881) were written. The Franco-German War of 1870-71 profoundly interested him, and evoked a plea for Germany. From this time his health began to give way more and more. In 1872 his right hand became paralysed.