The governing structure of Democratic Kampuchea was split between the state presidium which was headed by Khieu Samphan, the cabinet was led by Pol Pot who was also Democratic Kampuchea's prime minister and the party's own Politburo and Central Committee. All were complicated by a number of political factions which existed in 1975. The leadership of the Party Centre, the faction which was headed by Pol Pot, remained largely unchanged from the early 1960s to the mid-1990s. Its leaders were mostly from middle-class families and had been educated at French universities. The second significant faction was made up of men who had been active in the pre-1960 party and had stronger links to Vietnam as a result. However, government documents show that there were several major shifts in power between factions during the period in which the regime was in control.