The reform decade is usually seen as beginning in 1977–1978 when Deng Xiaoping returned to power after the death of Mao in 1976, and initiated a series of changes under the rubric of "four modernizations.” In the late 1970s and early 1980s, the most important area of reforms was in agriculture, with the dissolution of the communes, and the development of an agricultural responsibility system, allowing a degree of autonomy in rural areas unknown since the mid-1950s. The reform period began with a major national education conference in April 1978, which abandoned the Cultural Revolution goals of class struggle and adopted modernization as the main goal for educational development. There are many excellent analyses of the reform decade, from its early promise to its denouement in the major political crisis of 1989. Perhaps the greatest challenge of the market reforms and greater mobility of professional personnel will be that of geography.