 The Somalis are a Muslim ethnic group of between 15 and 20 million people, constituting the largest ethnicity in Somalia, many of whom also live in Ethiopia, Kenya, and Djibouti.They have historically exhibited social stratification that has included embedded castes referred to as "Higal" (or "Higalki", "Argobba").The upper noble strata has been called "Gob" (or Asha), while the lower servile strata have been referred to as "Sáb".