Tamara Eidelman, historian, writer, educator, and YouTube creator with over 1.5 million subscribers, lectures on 'How Nations Emerge and Disappear'. Centuries ago, identity was by faith, city, or lord—not nationality. Ancient Greeks shared language but not unity; medieval scholars crossed Europe freely. The 'national spirit' emerged in the late 18th century; 19th-century nationalism turned chauvinistic; 20th century showed dangers. Today, debates rage: biology, construct, or tool? Explores the idea's origins and resilient myths. In Russian, followed by Q&A.