The tribes speaking the Doric dialect of Greek who probably entered Greece from the north c.1100–1000 bc and by the 8th century bc had settled most of the Peloponnese, the southernmost Aegean islands, and the south-west corner of Asia Minor. While culturally distinct in architecture and dialect, the Dorians retained their political system only in Sparta and Crete where the ruling military class subjected the local peoples as serfs and dependants. The Dorians were responsible for the oldest and simplest orders of Greek architecture, known as the Doric order.