Following the destruction of Minoan palaces in LM I B, a new social reality emerged in Crete. Important economic and administrative changes occurred over a period of 250 years (LM II–III). Originally, a strictly centralized system was imposed by Knossos with the aim of securing authority over part of the island in LM II–III A 1. Later, in LMIII A 2 the economic and administrative system appears to have changed. This new system was decentralized and based on regional centres. Knossos was at the summit, a few powerful regional centres were subjects to the palace. In the LM III B period, after the final destruction of the palace of Knossos, the scene changes again. The economic system rested on independent regional centres of greater or smaller economic impact, which were scattered all over the island. The most important of these centres was undoubtedly Chania.