Tourism is a very strong economic sector and as such it can generate a great income to some countries. Throughout the twentieth century, tourism has experienced a great growth and it is considered as a very profitable business. But the twentieth century is also an era which was marked by the great global crisis and world wars that were not previously recorded in the world history. The theme of this thesis looks at the development of tourism throughout the dark period of the twentieth century and how the tourism survived and managed to develop itself into what it is today. By studying the available literature, it was determined what was the state of history of that time and what tourism, big wars and crises had in common. When chaos rules the world the sustainability of tourism is rather questionable, chaos can have a very negative impact on the overall economy of some countries and it can create a great sense of insecurity among people and, ultimately, endanger human lives. However, human nature is such that, despite all the disadvantages of history, the curiosity for discovering and traveling to new areas has only increased. In the twentieth century, apart from the wars and the crisis, major technological innovations were brought in all fields, and tourism was no exception.