Though the concept of a Shared universe was not new or unique to comic books in 1961, writer/editor Stan Lee, together with several artists including Jack Kirby and Steve Dikto, created a series of titles where events in one book would have repercussions in another title and serialized stories would show characters' growth and change. 

 The Marvel Universe is strongly based on the real world. Earth in the Marvel Universe has all the features of the real one: same countries, same personalities (politicians, movie stars, etc.), same historical events (such as World War II), and so on; however, it also contains many other fictional elements: countries such as Wakanda and Latveria (very small nations) and organizations like the espionage agency S.H.I.E.L.E.D. and its enemies, HYDRA and A.I.M. In 2009 Marvel officially described its world's geography in a two-part miniseries, the Marvel Atlas.