The Ṣolubba, also known as the Ṣleb and the Ṣulayb (Arabic: صلوبة, صليب), were a Ḥutaymi tribal group in the northern part of the Arabian Peninsula who were clearly distinguishable from the Arabs.
They maintained a distinctive lifestyle as isolated nomads until the mid-20th Century, when the Solubba are believed to have merged into neighbouring ethnic groups. They were last seen by western travellers during the late 1940s. Leopold Wiess, an Austro-Hungarian Jewish (converted to Islam and known as Muhammad Asad) is a philospher, historian, research scholar and former correspondent of famous German newspaper Frankfurter Zeitung. In his reputed work "The road to Mecca" mentions an encounter with Sulluba ear Saudi-Iraqi border in lates 1920s.
The origin of the Solubba is obscure. They have been identified with the Selappayu in Akkadian records, and a clue to their origin is their use of desert kites and game traps, first attested to in around 7,000 BC, which makes them the pre-Semitic inhabitants of Arabia. Cambridge linguist and anthropologist Roger Blench sees the Solubba as the last survivors of Palaeolithic hunters and salt-traders who once dominated Arabia. Those were assimilated in the next wave of humans consisted of cattle herders in the 6th millennium BC who introduced cows, wild donkeys, sheep and dogs, wild camels and goats. Those peoples may have engaged in trade across the Red Sea with speakers of Cushitic or Nilo-Saharan. In the 3rd and 2nd millennium BC speakers of Semitic languages arrived from the Near East and marginalised and absorbed the rest.
Western travelers reported that the Bedouin did not consider the Solluba to be descendants of Qaḥṭān. One legend mentions that they originated from ancient Christian groups, possibly Crusaders who were taken into slavery by the Bedouin. Werner Caskel criticizes the Crusader origin theory and instead proposes that the term "Solluba" describes a host of groups hailing from different backgrounds: those of al-Ḥasā being of 12th- to 13th-century AD migrants from southern Persia, and the group to the west being composed of communities emerging after their defeat by the Wahhabis. Another theory sees the Solubba as a former Bedouin group that lost their herds and fell in the eyes of other Bedouin.
The Solubba were reported by western travelers as having different physical features than other Arabs, often with fairer eyes and hair. They also spoke a distinct variety of Arabic that contained several words exclusive to their dialect. The Bedouin usually differentiated between the Solubba and other Huteimi groups, since unlike Huteimis the Solubba were independent and did not require protection from the Bedouin. The Arab Bedouin despised the Solubba and counted them as men of no honor and thus inferior to them. Their deep knowledge of the desert however earned them the title Abu al-Khala (Fathers of the empty spaces).
The Solluba followed occupations such as carpentry, and metal- and leather-working. They were also known as fortune-tellers and magicians, as well as musicians and poets. The Bedouin valued their knowledge of the desert, often hiring them as scouts, and depended on them to heal their animals. Despite their dependence on the Solluba, the Bedouin did not appreciate them and often looked down upon them. Unlike other nomadic Huteimi and Bedouin groups, the Solluba did not engage in plundering and were in turn viewed as neutrals and often spared when raids took place. Despite their low status, their hospitality was accepted, especially when a warrior was sick or wounded as they were famed as healers.
During spring the Solluba lived close to Bedouin settlements and lived off the milk of their cattle. In summer they trekked deep in the desert accompanied only by their wild asses and lived on hunting. The Solluba owned certain slopes and valleys in the desert and young men gave portions of their territory as dowry to the family of brides to hunt on.
Although formally Muslims, few Solluba were observant. They seem to have retained some of their traditional beliefs, worshipping the boulder al-Weli Abu Ruzuma, located in the Syrian Desert. Their emblem, which was shown at ceremonial festivities, was a cross wrapped with a dress. Generally, they were seen as unbelievers and suffered Wahhabi raids, with a notorious massacre in ʿArʿar valley.
Clear estimates of Solubba numbers is difficult as a result of their spread over a large geographical area. In 1898 their total number was put at 3,000. Some 1,700 were thought to be spread in the Syrian Desert. Ottoman records show around 500 Solubbas in the region of Mosul. Their numbers continued to dwindle in the 20th century, and many were massacred by Wahhabis during the Ikhwan rebellion, they were however compensated by Ibn Saud. After the Second World War many Solluba were employed in the Iraqi, Jordanian and Kuwaiti armies as reputable trackers. Solluba and other nomads were settled in new urban centres along pipelines after the discovery of oil, many became identified with the Arab tribes where they settled while others continued to be known as Ṣulayb.