The thesis of the Heilbrunn Timeline of Art History is simple: The Metropolitan Museum of Art is in a unique position to present the history of art through its unparalleled collection, which represents more than 5,000 years of art from across the globe—from the first cities of the Ancient Near East to works being created today. Integration of content across the publication—including thematic essays, chronologies, works of art, and keywords—is the key to the publication's success, in that every user has an unending path of discovery available to them. Anyone can begin their journey exploring 20th-century Cubist works of Fernand Léger and end their session learning about the Assyrian lamassu who guard the museum's first-century B.C. Assyrian Sculpture Court.