Adal Sultanate in the context of Cannons

The spread of Islam spans almost 1,400 years. The early Muslim conquests that occurred following the death of Muhammad in 632 CE led to the creation of the caliphates, expanding over a vast geographical area; conversion to Islam was boosted by Arab Muslim forces expanding over vast territories and building imperial structures over time. Most of the significant expansion occurred during the reign of the rāshidūn ("rightly-guided") caliphs from 632 to 661 CE, which were the first four successors of Muhammad. These early caliphates, coupled with Muslim economics and trading, the Islamic Golden Age, and the age of the Islamic gunpowder empires, resulted in Islam's spread outwards from Mecca towards the Indian, Atlantic, and Pacific Oceans and the creation of the Muslim world. The Islamic conquests, which culminated in the Arab empire being established across three continents (Asia, Africa, and Europe), enriched the Muslim world, achieving the economic preconditions for the emergence of this institution owing to the emphasis attached to Islamic teachings. Trade played an important role in the spread of Islam in some parts of the world, such as Indonesia. During the early centuries of Islamic rule, conversions in the Middle East were mainly individual or small-scale. While mass conversions were favored for spreading Islam beyond Muslim lands, policies within Muslim territories typically aimed for individual conversions to weaken non-Muslim communities. However, there were exceptions, like the forced mass conversion of the Samaritans.

Muslim dynasties were soon established and subsequent empires such as those of the Umayyads, Abbasids, Mamluks, Seljukids, and the Ayyubids were among some of the largest and most powerful in the world. The Ajuran and Adal Sultanates, and the wealthy Mali Empire, in North Africa, the Delhi, Deccan, and Bengal Sultanates, and Mughal and Durrani Empires, and Kingdom of Mysore and Nizam of Hyderabad in the Indian subcontinent, the Ghaznavids, Ghurids, Samanids in Persia, Timurids, and the Ottoman Empire in Anatolia significantly changed the course of history. The people of the Islamic world created numerous sophisticated centers of culture and science with far-reaching mercantile networks, travelers, scientists, hunters, mathematicians, physicians, and philosophers, all contributing to the Islamic Golden Age. The Timurid Renaissance and the Islamic expansion in South and East Asia fostered cosmopolitan and eclectic Muslim cultures in the Indian subcontinent, Malaysia, Indonesia and China. The Ottoman Empire, which controlled much of the Middle East and North Africa in the early modern period, also did not officially endorse mass conversions, but evidence suggests they occurred, particularly in the Balkans, often to evade the jizya tax. Similarly, Christian sources mention requests for mass conversions to Islam, such as in Cyprus, where Ottoman authorities refused, fearing economic repercussions.

Ethiopia is one of the oldest countries in Africa; the emergence of Ethiopian civilization dates back thousands of years. Abyssinia or rather "Ze Etiyopia" was ruled by the Semitic Abyssinians (Habesha) composed mainly of the Amhara, Tigrayans and the Cushitic, Oromo and Agaw. In the Eastern escarpment of the Ethiopian highlands and more so the lowlands were the home of the various Muslim groups that formed the Ifat and Adal sultanates such as the Argobba, Afars, Harari/Harla and Somalis. In the central and south were found the ancient Sidama, Semitic Gurage and Omotic Wolaita, among others.One of the first kingdoms to rise to power in the territory was the kingdom of Damot in the 10th century BC, which established its capital at Yeha. In the first century AD, the Aksumite Kingdom rose to power in the modern Tigray Region with its capital at Aksum and grew into a major power on the Red Sea, subjugating South Arabia and Meroe and its surrounding areas. In the early fourth century, during the reign of Ezana, Christianity was declared the state religion and not long after, the Aksumite empire fell into decline with the rise of Islam in the Arabian peninsula, which slowly shifted trade away from the Christian Aksum. It eventually became isolated, its economy slumped and Aksum's commercial domination of the region ended. The Aksumites gave way to the Zagwe dynasty, who established a new capital at Lalibela before giving way to the Solomonic dynasty in the 13th century. During the early Solomonic period, Ethiopia underwent military reforms and imperial expansion, allowing it to dominate the Horn of Africa.

Djibouti, officially the Republic of Djibouti, is a country in the Horn of Africa, bordered by Somalia to the south, Ethiopia to the southwest, Eritrea in the north, and the Red Sea and the Gulf of Aden to the east. The country has an area of 23,200 km (8,958 sq mi).

In antiquity, the territory, together with Ethiopia, Eritrea and Somaliland, was part of the Land of Punt. Nearby Zeila, now in Somaliland, was the seat of the medieval Adal and Ifat Sultanates. In the late 19th century, the colony of French Somaliland was established after the ruling Dir, Somali, and Afar sultans signed treaties with the French, and its railroad to Dire Dawa (and later Addis Ababa) allowed it to quickly supersede Zeila as the port for southern Ethiopia and the Ogaden. It was renamed the French Territory of the Afars and the Issas in 1967. A decade later, the Djiboutian people voted for independence. This officially marked the establishment of the Republic of Djibouti, named after its capital city. The new state joined the United Nations in its first year. In the early 1990s, tensions over government representation led to armed conflict, which ended in a power-sharing agreement in 2000 between the ruling party and the opposition.

Somalia, officially the Federal Republic of Somalia, is the easternmost country in continental Africa. Stretching across the Horn of Africa, it borders Ethiopia to the west, Djibouti to the northwest, Kenya to the southwest, the Gulf of Aden to the north, and the Indian Ocean to the east. Somalia has the longest coastline on Africa's mainland. Somalia has an estimated population of 18.1 million, of which 2.7 million live in the capital and largest city, Mogadishu. As one of Africa's most ethnically homogenous countries, around 85% of its residents are ethnic Somalis. The official languages of the country are Somali and Arabic, though Somali is the main language. Somalia has historic and religious ties to the Arab world. The overwhelming majority of the population are Sunni Muslims.

In antiquity, Somalia was an important commercial centre. During the Middle Ages, several powerful Somali empires dominated the regional trade, including the Ajuran Sultanate, Adal Sultanate, and the Sultanate of the Geledi. In the late 19th century, the Somali sultanates were colonised by the Italian and British empires, who merged all of these tribal territories into two colonies: Italian Somaliland and British Somaliland. In 1960, the two territories united to form the independent Somali Republic under a civilian government. Siad Barre of the Supreme Revolutionary Council (SRC) seized power in 1969 and established the Somali Democratic Republic, brutally attempting to squash the Somaliland War of Independence in the north of the country. The SRC collapsed in 1991 with the onset of the Somali Civil War. The Transitional National Government of Somalia (TNG) was established in 2000, followed by the formation of the Transitional Federal Government of Somalia (TFG) in 2004, which reestablished the Somali Armed Forces.

Somaliland, officially the Republic of Somaliland, is an unrecognised state in the Horn of Africa. It is located on the southern coast of the Gulf of Aden and bordered by Djibouti to the northwest, Ethiopia to the south and west, and Somalia to the east. Its claimed territory has an area of 176,120 square kilometres (68,000 sq mi), with approximately 6.2 million people as of 2024. The capital and largest city is Hargeisa.

Various Somali Muslim kingdoms were established in the area during the early Islamic period, including in the 14th to 15th centuries the Zeila-based Adal Sultanate. In the early modern period, successor states to the Adal Sultanate emerged, including the Isaaq Sultanate, which was established in the middle of the 18th century. In the late 19th century, the United Kingdom signed agreements with various clans in the area, establishing the Somaliland Protectorate, which was formally granted independence by the United Kingdom as the State of Somaliland on 26 June 1960. Five days later, the State of Somaliland voluntarily united with the Trust Territory of Somaliland (the former Italian Somalia) to form the Somali Republic. The union of the two states proved problematic early on, and in response to the harsh policies enacted by Somalia's Barre regime against the main clan family in Somaliland, the Isaaq, shortly after the conclusion of the disastrous Ogaden War, a 10-year war of independence concluded with the declaration of Somaliland's independence in 1991. The Government of Somaliland regards itself as the successor state to British Somaliland.

The Ethiopian–Adal War, also known as the Abyssinian–Adal War and Futūḥ Al-Ḥabaša (Arabic: فتوح الحبش, lit. 'Conquest of Abyssinia'), was a war fought between the Christian Ethiopian Empire and the Muslim Adal Sultanate from 1529 to 1543. The Christian Ethiopian troops consisted of the Amhara, Tigrayans, Tigrinya and Agaw people, and at the closing of the war, supported by the Portuguese Empire with no less than four hundred musketeers. The Adal forces were composed of Harla/Harari, Somali, Afar as well as Arab and Turkish gunmen. Both sides would see the Maya mercenaries at times join their ranks. The conflict was followed shortly by the 16th century Ottoman-Ethiopian War

Ethiopians are the native inhabitants of Ethiopia, as well as the global diaspora of Ethiopia. Ethiopians constitute several component ethnic groups, many of which are closely related to ethnic groups in neighboring Eritrea and other parts of the Horn of Africa.

The first documented use of the name "Ethiopia" from Greek name Αἰθίοψ, Aithíops was in the 4th century during the reign of Aksumite king Ezana. There were three ethnolinguistic groups in the Kingdom of Aksum: Semitic, Cushitic, and Nilo-Saharan (ancestors of the modern-day Kunama and Nara). The Kingdom of Aksum remained a geopolitically influential entity until the decline of its capital — also named Axum — beginning in the 7th century. Nevertheless, the core Aksumite civilization was preserved and continued into the successive Zagwe dynasty. By this time, new ethnic groups emerged – the Tigrayans and Amharas. During the Solomonic period, the latter established major political and cultural influence in the Horn of Africa.In the Late Middle Ages, Muslim states were established, including the Sultanate of Ifat, and its successor the Adal Sultanate. Discontent with territory and religious dominance led to intense war between the Ethiopian Empire, the Christian state (consisting of the Amhara, Tigrayan, Soddo Gurage, and Agaw ethnic groups) and the Muslim state Adal Sultanate (consisting of Semitic-speaking Harari formally known as the Harla people, and the Argobba). During the 1600s, there were large-scale migrations of the Oromo from the south into the highlands and also alongside the Somali into Adal or what was known as "Hararghe" (land of the Hararis).

The Oromo expansions or the Oromo invasions (in older historiography, Galla invasions), were a series of expansions in the 16th and 17th centuries by the Oromo primarily documented by the Gamo monk Bahrey, but also mentioned in other Christian, Muslim and Portuguese records. Prior to their great expansion in the 16th century, the Oromo inhabited only the area of what is now modern-day southern Ethiopia and northern Kenya. Over the centuries, many factors – mostly the wars between the Adal Sultanate and the Ethiopian Empire – would further encourage the numerous Oromo tribes to expand towards what is now central and eastern Ethiopia.

Somali–Portuguese conflicts refers to the armed engagements between Portuguese forces and Somali forces, namely those of the Adal Sultanate and the cities of Barawa and Mogadishu in the 16th century.

Portugal made a notable intervention in the Ethiopian–Adal War on the side of Christian Ethiopia and although Cristóvão da Gama, the commander of the Portuguese expeditionary corps was captured and executed for not converting to Islam, the remaining Portuguese continued the campaign, and Ethiopia was ultimately defended successfully.

Sabr ad-Din III (Arabic: الصبر الدين الثالث) (died 1422 or 1423) was a Sultan of the Adal Sultanate and the oldest son of Sa'ad ad-Din II. Sabr ad-Din returned to the Horn of Africa from Yemen to reclaim his father's realm. He defeated the Ethiopians and proclaimed himself "King of Adal". He subsequently became the first ruler and founder of the new Adal dynasty.

Badlāy ibn Saʿd ad-Dīn II (Arabic: بدلاي بن سعد الدين) (also known as Shihāb ad-Din Aḥmad Badlāy, Arwe Badlay – "Badlay the Beast" (died 25 December 1445) was a Sultan of the Adal Sultanate and a son of Sa'ad ad-Din II. Brought numerous Christian lands under Muslim rule and contributed to expanding Adal's reach and power in the region. The polity under Sultan Badlay controlled the territory stretching from port city of Suakin in Sudan to covering the whole Afar plains to the Shewa and Chercher Mountains to include a significant part of northern Somalia.

Jamal ad-Din II (Arabic: جمال الدين الثاني) (died 1433) was a Sultan of the Adal Sultanate. He was the youngest son of Sa'ad ad-Din II.

Mahfuz (or Mohammed) (Harari: መሕፉዝ, Arabic: محفوظ, Portuguese: Mafudi, Somali: Maxfuud; died July 1517) was a Garad, Emir of Harar and Governor of Zeila in the Adal Sultanate. Although he was originally only emir of a small region he would rise to become leader of Adal due to his popularity, wielding more power than the sultan of Adal. He is often known as the "Captain of Zeila" in medieval texts.

Ahmad ibn Ibrahim al-Ghazi (Arabic: أحمد بن إبراهيم الغازي, Harari: አሕመድ ኢብራሂም አል-ጋዚ, Somali: Axmed Ibraahim al-Qaasi; c. 21 July 1506 – 10 February 1543) was the Imam of the Adal Sultanate from 1527 to 1543. Commonly named Ahmed Gragn in Amharic and Gurey in Somali, both meaning the left-handed, he led the invasion and conquest of Abyssinia from the Sultanate of Adal during the Ethiopian–Adal War. He is often referred to as the "King of Zeila" in medieval texts.

Dubbed "The African Attila" by Orientalist Frederick A. Edwards, Imam Ahmed's conquests reached all the way to the borders of the Sultanate of Funj. Imam Ahmed won nearly all his battles against the Ethiopians before 1541 and after his victory at Battle of Amba Sel, the Ethiopian Emperor, Dawit II was never again in a position to offer a pitched battle to his army and was subsequently forced to live as an outlaw constantly hounded by Imam Ahmed's soldiers, the Malassay. Ahmed Gragn was subsequently defeated following a Portuguese intervention, which drew his war into a broader geo-political struggle between the Portuguese and Ottoman empires. The memory and legacy of his invasion nonetheless persists in both modern Ethiopia and Somalia.

Nur al-Din or Nur ibn Mujahid ibn ‘Ali ibn ‘Abdullah al Dhuhi Suha (Harari: ኑር ኢብን ሙጃሂድ, Somali: Nuur ibn Mujaahid, Arabic: نور بن مجاهد; died 1567) was an Emir of Harar who ruled over the Adal Sultanate. He was known for his victory in Fatagar against Ethiopian forces and for marrying his uncle's widow, Bati del Wambara. He succeeded Imam Ahmad Ibn Ibrahim as the leader of the Muslim forces against Christian Ethiopia by defeating the Emperor Galewdewos in battle in 1559. He is often cited as the "King of Adel" in medieval texts.