In the nineteenth century the Kichagga-speaking people on Mount Kilimanjaro were divided into many small, autonomous chiefdoms. Early accounts frequently identify the inhabitants of each chiefdom as a separate "tribe." Although the Chagga are principally located on Mount Kilimanjaro in northern Tanzania, numerous families have migrated elsewhere over the course of the twentieth century. Exogamous patrilineages are the basic building blocks of the kinship system. These are sometimes called "clans" in the colonial literature. They vary in size from a few households to many dozens. Marriage is virilocal, and many lineages are localized because of the link between kinship and land tenure.