The International Heliophysical Year (IHY) is an international program of scientific research and collaboration to understand the external drivers of the space environment and climate. Its activities were centered on the year 2008, the 50th anniversary of the International Geophysical Year. The IHY involves utilizing the existing assets from space and ground as a distributed Great Observatory and the deployment of new instrumentation, new observations from the ground and in space, and public and student education. The IHY officially was launched in February 2007 with an opening ceremony and workshop in Vienna. Many IHY activities, both scientific and educational, have occurred since then. In practice, these activities have taken place over the last several years, and the programs that have been established through the IHY will continue into the future as ‘legacies’ of the IHY.