Bunsen's life as a public man was now practically at an end. He retired first to a villa on the Neckar near Heidelberg and later to Bonn. He refused to stand for a seat, in the Liberal interest, in the Lower House of the Prussian diet, but continued to take an active interest in politics, and in 1855 published in two volumes a work, Die Zeichen der Zeit: Briefe, etc., which exercised an immense influence in reviving the Liberal movement which the failure of the revolution had crushed. In September 1857 Bunsen attended, as the king's guest, a meeting of the Evangelical Alliance at Berlin; and one of the last papers signed by Frederick william, before his mind gave way in October, was that which conferred upon him the title of baron and a peerage for life. In 1858, at the special request of the regent (afterwards the emperor) william, he took his seat in the Prussian House of Lords, and, though remaining silent, supported the new ministry, of which his political and personal friends were members.