Paul Allen discusses current views on Lenin, the founder and first leader of the Soviet Union, as a new biography uses material from recently opened archives to piece together the public and private lives of one of the colossal figures of modern history. And a new translation of the Icelandic sagas prompts reassessment of some of the greatest works of the medieval world. Plus the last of this week's series on Africa, which looks today at tribal values and conflict in contemporary Nigerian culture.