The group first appeared in the latter half of 2015 when pro-Islamic State fighters within al-Shabaab defected and pledged allegiance to ISIS caliph Abu Bakr al-Baghdadi.

While cells have periodically appeared in southern Somalia and Kenya, the primary area of operations for ISS is the Al-Madow and Golis Mountains in Puntland, where the presence of both al-Shabaab and state authorities is weak.

[10][11] As of September 2024, foreign fighters possibly outnumber the groups Somali members, with Ethiopians reportedly being the single largest demographic represented within the organization.

[8] Notably ISS is also the declared enemy of al-Shabaab, which considers the Islamic State a significant threat to its own predominance among Jihadist factions in Somalia.

As a cleric with little military experience, Mumin's role in Puntland was originally to attract recruits for the numerically small and militarily weak local al-Shabaab group, which was led by Mohamed Said Atom at the time.

This was however not tolerated by the Somali organization, which released statements condemning dissenters[a] and ordered its internal security service Amniyat to arrest or kill pro-IS elements such as Hussein Abdi Gedi's faction in Middle Juba.

Mumin's small group proceeded to form Abnaa ul-Calipha, better known as Islamic State in Somalia, and to evade their erstwhile comrades, while recruiting new members for their cause.

In two notable incidents in November and December 2015, al-Shabaab attacked and destroyed two of the most important southern IS cells, namely the ones of Bashir Abu Numan and Mohamed Makkawi Ibrahim.

As result, IS forces in southern Somalia remained very weak,[17] and those that survived appear to have accepted Mumin's authority over time, formally becoming part of ISS.

[25] Overall, ISS suffered numerous casualties during the Qandala campaign,[24] but had scored a symbolic victory nonetheless, having captured and held a major town for more than a month.

When the ISS suicide bomber tried to close in on the Juba Hotel in Bosaso, he was stopped at a military checkpoint, causing him to detonate his explosives, killing five and wounding twelve.

[32][33] In June 2017, a Puntland military official claimed that ISS had been reduced to around 70 active fighters, and sustained itself by stealing food and livestock from local communities.

[34] Regional expert Matthew Bryden, on the other side, said that ISS still had up to 300 fighters and had become entrenched in the eastern Galgala mountains, where it had gained the support of some local communities which felt ignored by the government.

[35] Observers also noted that ISS had significantly increased their output of propaganda material in an attempt to sway disenfranchised locals[26] and international jihadists to their side.

[22] By May 2018, ISS had reportedly carried out eleven attacks and killed 23 people who had allegedly worked for the government, such as intelligence agents, soldiers, officials, and policemen.

[22] At some point in 2018, ISS managed to convince a significant number of al-Shabaab militants to defect, resulting in the formation of an Islamic State cell in Beledweyne.

In these works, the Islamic State was sharply rebuked as corrupt, apostate, and seditionist force, while al-Shabaab authorized its loyalists to destroy ISS elements as "disease in the Jihad".

[28] The United States Air Force carried out an airstrike against ISS on 14 April 2019, killing its deputy Abdihakim Mohamed Ibrahim at Xiriiro, Bari region.

Bilal al-Sudani was responsible for fostering the growing presence of ISIS in Africa and funding the group's operations worldwide, including in Afghanistan.

Uncharacteristically, ISS has so far not imposed strict rules on the local populations it has come into contact with, though have recently began carrying assassinations, bombings and kidnappings in Bosaso.

[64][65] The Islamic State in Somalia is led by Abdul Qadir Mumin, whose role in the continued existence of the group has been judged to be extremely important.

[66] Described as "eloquent and persuasive, [...] very savvy and sophisticated", Mumin is deeply involved in international jihadism and considered to be an extremely dangerous terrorist leader.

After reports circulated in June/July 2017 that Abu Bakr al-Baghdadi had been killed, terror expert Candyce Kelshall even speculated that Mumin might be tempted to declare himself the new caliph of IS.

[67][48] Though it is probable[68] that ISS controls a relatively small territory in Puntland's mountainous hinterland,[35] the group is not known to have attempted to set up something resembling a government at any point of its existence.

[69] It has occasionally highlighted its “healthcare services” in the remote villages in Puntland in its propaganda videos, showing a Somali-Canadian doctor named “Yusuf al-Majerteeni”, who died in 2018.

[74] The vast majority of ISS members are Somalis, with only a few foreign mujahideen fighting for the group, including Sudanese, Yemenis,[68][37] Ethiopians,[2][71] Egyptians,[47] Djiboutis, and at least one Canadian.

[75] This influx of foreign fighters significantly bolstered ISS's strength, with the groups members being numbered at 600 to 700 according to a United Nations Security Council report from 2024.

As result, local clans (including Mumin's own, the Majeerteen Ali Saleban) are aggrieved by their perceived marginalisation by the government and in some cases ready to support ISS.

[22] The group is also directly supported by the Islamic State of Iraq and the Levant – Yemen Province, which is known to have sent experts, trainers, money, weapons and other materials to ISS.

[68][37] In smuggling fighters and supplies across the Gulf of Aden, ISS works closely with Somali pirates, namely Mohamed Garfanje's Hobyo-Haradhere Piracy Network and another unidentified group that is based in Qandala.