The Dervish Movement (Somali: Dhaqdhaqaaqa Daraawiish) also known as the Dervish State was an armed resistance movement and polity headquartered in Taleh between 1895 and 1920, which was led by the Salihiyya Sufi Muslim poet and militant leader Mohammed Abdullah Hassan, also known as Sayyid Mohamed, who called for independence from the British and Italian colonisers and for the defeat of Ethiopian forces. The Dervish movement aimed to remove the British and Italian influence from the region and restore an "Islamic system of governance with a Sufi doctrine as its foundation", according to Mohamed-Rahis Hasan and Salada Robleh.

Hassan established a ruling council called the Khususi consisting of Sufi tribal elders and spokesmen, added an adviser from the Ottoman Empire named Muhammad Ali, and thus created a multi-clan Islamic movement in what led to the eventual creation of the state of Somalia.

The Dervish movement attracted approximately 25,000 youth from different clans over 1899 and 1905, acquired firearms and then attacked the Ethiopian garrison at Jigjiga. The Dervishes were able to take the cattle seized from the local Somalis, giving them their first military victory. The Dervish movement then declared the colonial administration in British Somaliland as their enemy. To end the movement, the British sought out the competing Somali clans as coalition partners against the Dervish movement. The British provided these clans with firearms and supplies to fight against the Dervishes. Punitive attacks were launched against Dervish strongholds in 1904. The Dervish movement suffered losses in the field, regrouped into smaller units and resorted to guerrilla warfare. Hasan and his loyalist Dervishes moved into the Italian-controlled Somaliland in 1905 after Hasan signed the Illig treaty, under which the Dervishes were ceded the Nugaal Valley, which strengthened his movement, and Hasan subsequently received an Italian subsidy and autonomous protected status.

In 1908, the Dervishes again entered British Somaliland and began inflicting major losses to the British in the interior regions of the Horn of Africa. From 1908 onwards until the end of the World War I the British retreated to the few remaining coastal regions after suffering heavy losses in the interior to which the Dervish continued to operate independently and leaving the interior regions in the hands of the Dervishes. During 1905-1910, the Dervishes continued raids against the remaining British who were defeated in the battle of Dul Madooba.

The Dervish movement led by Sayyid Muhammed Abdullah Hassan, continued independently from about (24–26) years between 1896/1900–1921. The Dervish movement had successfully repulsed the British Empire four times and forced it to retreat to the coastal region. Because of these successful expeditions, the Dervish movement was recognized as an ally by the Ottoman and German empires during the First World War. The Turks referred to the Sayyid as the Emir of the Somali nation, and the Germans promised to officially recognise any territories the Dervishes were to acquire. After a quarter of a century of holding the British at bay and with the end of the First World War leading to the defeat of the Dervish allies the Ottoman and German empires following the end of World War I, the British turned their attention to the Dervishes. In 1920, the British launched a massive combined arms offensive on the Taleh forts, strongholds of the Dervish movement. The offensive caused significant casualties among the Dervishes, although the Dervish leader Mohammed Abdullah Hassan managed to escape. His death in 1921 due to either malaria or influenza ended the Dervish movement.

The Dervish movement temporarily created a mobile Somali "proto-state" in early 20th-century with fluid boundaries and fluctuating population. It was one of the bloodiest and longest militant movements in sub-Saharan Africa during the colonial era, one that overlapped with World War I. The battles between various sides over two decades killed nearly a third of Somaliland's population and ravaged the local economy. Scholars variously interpret the emergence and demise of the militant Dervish movement in Somalia. Some consider the "Sufi Islamic" ideology as the driver, others consider economic crisis to the nomadic lifestyle triggered by the occupation and "colonial predation" ideology as the trigger for the Dervish movement, while post-modernists state that both religion and nationalism created the Dervish movement.

According to Abdullah A. Mohamoud, traditional Somali society followed a decentralized structure and a nomadic lifestyle dependent on livestock and pastureland. It was also predominantly Muslim. By the close of the 19th century, the European colonial powers expanded their reach in the Horn of Africa, and the region of Somalia came under the influence of the British, the Ethiopians and the Italians. The withdrawal of the Egyptian troops from Harar enabled Ras Makonnen and Menelik II to expand the burgeoning Ethiopian realm eastward into the Ogaden territory. In 1884, Britain established a protective authority over Somaliland, aiming to safeguard Aden and the Bab-el-Mandeb strait's strategic interests in the Red Sea. By 1893, following arduous negotiations, an Italian chartered company assumed control over the Benadir coastline in southern Somalia, with the remainder of the region placed under an Italian protectorate in 1889. With foreign rule came the centralization of the economy, which greatly upset the traditional livestock and pastureland based livelihood of the Somalis. The foreign powers were also all Christians, which created additional suspicions amongst the Somali religious elite. The Ethiopian troops had already proved to be a bane for the Somalis as they were the traditional raiders and plunderers of their grazing herds. The arrival of the colonial powers and the consequent partitioning of Africa greatly affected the Somalis, with Sufi poets such as Faarax Nuur writing poems expressing his opposition to foreign rule. The Dervish movement can thus be seen as a reaction against the establishment of foreign control in Somalia.

The Dervish movement was led by a Sufi poet and religious nationalist leader named Mohammed Abdullah Hassan, also known as Sayid Maxamad Cabdulle Xasan. He was born in the Sacmadeeqo Lake, a location seven miles north of the town of Buuhoodle, sometime between 1856 and 1864 to a father who was a religious teacher. He studied in Somali Islamic seminaries and later went on Hajj to Mecca where he met Shaykh Muhammad Salah of the Salihiya Islamic Tariqah, which states The Encyclopedia Britannica was a "militant, reformist, and puritanical Sufi order". The preachings of Salah to Hasan had roots in Saudi Wahhabism, and it considered it a religious duty "to wage a holy war (jihad) against all other forms of Islam, the Western and Christian presence in the Muslim world, and a religious revival", state Richard Shultz and Andrea Dew. When Hasan returned to the Horn of Africa, the Somali tradition states that he saw Somali children being converted to Christianity by missionaries in the British colony. Hasan began preaching against this religious conversion and the British presence. He earned the ire of the British colonial administration, who pejoratively referred to him as "the mad mullah";his Sufi teachings were also opposed by the rival Qadiriya Tariqah – another traditional Sufi group of the region, states Said M. Mohamed. Another version of the early events link the illegal sale of a gun to Hasan by a corrupt Somali officer in 1899, who reported his gun as stolen rather than purchased by Hasan. The British authorities demanded the gun's return, while Hasan replied that the British should leave the country, a sentiment he had previously claimed in 1897 when he declared himself "the leader of a sovereign nation". Hasan continued to preach against the British introduction of Christianity to Somalia, stating that the "British infidels have destroyed our [Islamic] religion and made our children their children".