The Soviet and Chinese Aid Missions established in 1958 and 1959 were the first important non-Muslim presences in North Yemen. Following the September 1962 revolution, the Yemen Arab Republic became closely allied with and heavily dependent upon Egypt. Saudi Arabia aided the royalists in their attempt to defeat the Republicans and did not recognize the Yemen Arab Republic until 1970. At the same time, Saudi Arabia maintained direct contact with Yemeni tribes, which sometimes strained its official relations with the Yemeni Government. Saudi Arabia remained hostile to any form of political and social reform in Yemen and continued to provide financial support for tribal elites.