The infamous face of terror was succeeded by his number two, Ayman al-Zawahiri, who inherited leadership over the group's global terror operations.
But following a heated exchange between Zawahiri and Abu Bakr al-Baghdadi – the leader of the Islamic State in Syria and al-Sham – over the brutal behavior exhibited by the latter's group and its leader's insubordination, Zawahiri excommunicated ISIS from breaking their alliance.
Baghdadi's challenge to Zawahiri's leadership reached its climax when the former unilaterally declared himself as Caliph, the political successor to Muhammad – thereby elevating his status above Zawahiri.
The new reality forced international jihadi groups to pick sides in an internal conflict. So far, most of the large, organized groups – especially those already allied to al-Qaeda – like al-Qaeda in the Arabian Peninsula, al-Qaeda in the Islamic Maghreb, al-Shabaab, and Jabhat al-Nusra have reasserted their allegiance to Zawahiri.
But even within those loyal factions, dissenting voices of support for ISIS were heard, and some even provided advice on how the Islamic State can properly withstand the US attacks on the group.
Organizations which identify with global jihad, and have are not formally allied to al-Qaeda, have expressed both indirect and outright support of the Islamic State's methods and its aim to establish a global Islamic caliphate; the aura of success radiating from the organization has charmed many potential suitors.
These statements of support also help contextualize the declaration of Boko Haram's leader, who announced the establishment of an emirate in Nigeria. At the same time, there are more signs pointing to a new alliance between Ansar Bait al-Maqdis, the Salafi jihadi group operating in the Sinai, and the Islamic State.
This connection was revealed after the release of an investigation of a senior member in the group which was involved in the murder of 25 Egyptian soldiers in August 2013 and later in the beheading of Egyptian soldiers – much in the style of ISIS.
The signs point to an organization, which originally declared allegiance to Zawahiri, on the cusp of changing its colors.
Information revealed during the investigations of the Egyptian group's members definitively cements the close operational and logistical ties between the organizations, and that the Sinai faction is expected to soon announce its allegiance to the Islamic State.
At this stage it is still too early to declare with certainty that ISIS has won the popularity contest. But there is no doubt that the possibility has weighed heavily on Zawahiri, who rushed to announce the establishment of a new al-Qaeda delegation in the Indian subcontinent in recent days.
As far as Israel is concerned, there is cause for concern of a potential alliance between the global jihadi groups operating on its borders. An alliance between Ansar Bait al-Maqdis and the Islamic State poses a threat, as the Sinai group has launched several attacks on Israel, both on the border and by firing on Eilat.
The existing alliance between Ansar Bait al-Maqdis and the Salafi jihadi Gazan group – the Mujahideen Shura Council of Jerusalem – has already raised the current threat level, and increased the importance of Israel's strategic partnership with Egypt in the war on terror.
Yoram Schweitzer is the Director of the Terrorism and Low-Intensity Warfare Research Project at the Institute for National Security Studies. Shani Avita is a fellow at the institute.