Some texts refer to these two mainly agriculturist clans of Digil and Rahanwayn as Sab. However, members of the Digil and Rahanwayn and most Somalis consider the appellation Sab derogatory. Used as a common noun meaning "ignoble," the term sab was applied by the Samaal to groups that pursued certain disdained occupations. The Samaal felt that the Sab had lowered themselves by their reliance on agriculture and their readiness to assimilate foreign elements into their clans. Traditionally, the Rahanwayn are considered a Digil offshoot that became larger than the parent group.

The social structure of the Sab resembled that of the Samaal in that it was based on descent groups. However, there were significant differences. Sab clans were confederations of lineages and included persons originating in all-Somali clanfamilies as well as assimilated peoples. They came into being through a pact between the original founding segments, one of which, of Sab origin, was dominant; the name of the Sab segment became the name of the clan. By the twentieth century, the descendants of that dominant lineage often constituted only a relatively small core of the clan. The constituent lineages of the clan tended to have much shallower genealogies than the Samaal. Another important difference between the nomadic Samaal societies and the sedentary Sab was in the significance accorded to territoriality. Sab clans lived within distinct borders. The entire clan (or large subclan) often constituted the diya- paying group in relation to other clans. The term reer, which the Samaal used in connection with descent, was used by the Sab with a place name, e.g., reer barawa ("children of Baraawe").

Many clans were segmented into three subclans, called gember, although some, such as the Jiddu clans of the Digil clan-family, had only two subclans. Clans and subclans usually had single heads. In some cases, however, as among the Helai clans of the Rahanwayn, there were no clan heads. Clan affairs were handled by leading elders called gobweyn, who had assistants called gobyar.

Clans and subclans were subdivided into lineages that reckoned three to five generations from ancestor to youngest member. The lineage traditionally owned land and water rights, which the head men distributed to individual lineage members.

The manner in which Sab clans were formed led to recognized social inequalities, sometimes marked by differences in physical appearance owing to intermarriage within a stratum. Each stratum in a community consisted of one or more lineages. The basic distinction was between nobles (free clansmen) and habash, a group made up of pre-Somali cultivators and freed slaves.

In some Rahanwayn and Digil communities, there was a further distinction between two sets of nobles. Within the Geledi clan (located in Afgooye, just north of Mogadishu, and its environs) studied by anthropologist Virginia Luling, the nobles were divided into Darkskin and Lightskin categories, designations corresponding to the physical appearance of their members. The Darkskins were descendants of the core or founding group of the Geledi; the Lightskins had a separate line of descent, claimed partly Arab origin, and resembled the Arab populations of the old coastal towns. They had been completely Somalized, however. The wealth and position of the Lightskins were similar to that of the Darkskins, but the latter had precedence in certain traditional rites.

Each lineage (which consisted of perhaps 300 to 400 persons), or Darkskins, Lightskins, and habash, had its own set of elders and constituted a diya-paying group vis-à-vis the others, but was bound in a common contract concerning rates of compensation for injuries. In principle, habash lineages had equal rights under this system. Each lineage controlled specific segments of the land and allocated to an individual male as much as his family could cultivate. However, only the habash were subsistence cultivators in the nineteenth and the early twentieth centuries. The nobles, whether Darkskins or Lightskins, cultivated much larger areas by means of slave labor and exported surpluses via the coastal ports to Arab lands. In the case of the Geledi, wealth accrued to the nobles and to the sultan not only from market cultivation but also from involvement in the slave trade and other enterprises, such as commerce in ivory, cotton, and iron. The Geledi also raised cattle.

The sultan of the Geledi (a member of the Darkskin stratum) had a political and religious role. He also wielded somewhat greater authority than the sultans of the Samaal clans, but this authority was by no means absolute.

The sociopolitical organization and processes of the Geledi resembled those of many Digil and Rahanwayn communities. Not all such communities had a Lightskin component, and many were not located as auspiciously as the Geledi, for whom trade developed as a major economic factor. Most, however, had slaves who worked the land of the nobles.

The sedentary Somali communities in the coastal and interriverine areas, some of which were of Samaal origin, were more strongly affected by the advent of European colonization than the nomadic pastoralists were. Clans, and occasionally large lineages, came to have government chiefs appointed by colonial authorities, sometimes where there had been no chiefs of any kind. For the Geledi, the most important such chief was the sultan. Whatever his origin, the government-appointed chief was expected to be the intermediary between the colonial government and the people.

The abolition of the slave trade and the outlawing of slavery by 1920 changed not only the lives of the slaves but also the position of the nobles whose economic and political power depended on the slave economy. In Geledi areas and elsewhere, many slaves left to take up other land as subsistence cultivators. A few remained, and their descendants maintained a quasi-dependent relationship as clients of their former masters. By the second decade of the twentieth century, nobles were faced for the first time with having to cultivate their own land. None of the groups--nobles, habash, or ex-slaves--worked voluntarily for wages on the Italian plantations established at that time; colonial authorities usually made such labor mandatory.

Despite the radical social, political, and economic changes brought about by colonization, the nobles retained their superior position in Geledi (and probably in other Rahanwayn and Digil) communities. The nobles' status positioned them to profit from new income opportunities such as paid employment with the Italians or trade in the growing Afgooye market. They benefited from such business opportunities throughout the colonial period, as well as from educational and political opportunities, particularly during the trusteeship period (1950-60). Independence introduced still other changes to which the nobles responded.