The DARPA grand challenges were conducted between 2004 and 2007 and were initiated to foster research in the area of autonomous vehicles. While the first two challenges in 2004 and 2005 dealt with driving in unknown and rough environments without any moving obstacles, the challenge in 2007 increased the overall complexity by requiring correct and safe handling of moving vehicles from other competing autonomous vehicles in an urban setting. The first competition held in 2004 afforded no winner, while the repeated competition in 2005 produced five vehicles which finished the entire course from which four stayed under the ten hour time limit; Stanley the vehicle which was developed at Stanford University was the winner of this first international competition. After a period of less than two years, the community achieved the increased requirements for dealing with real urban-like traffic and afforded six autonomous vehicles from 89 applicants which finished the course within the timelimit. This chapter gives a short overview of the history of the Grand Challenges, discusses the background of the Urban Challenge, as well as goes over high level rules and the qualifying process. The remaining chapters in the book cover aspects of the development of autonomous vehicles ranging from appropriate sensor technology and setup, over reliable detection of the vehicle's surroundings, up to evaluating the environment for deriving a driving decision are covered in the following chapters. Besides, proper software and system development methods are discussed as well.