A comprehensive "annual report" by the fighters leading the Islamist takeover of parts of northern Iraq reveals sophisticated methods and their plans to control cities and govern regions.
The Isis annual report "al-Naba", published earlier this year in March, showed activities between November 2012 and 2013.
First published in Arabic, and running to 400 pages, it is the second known document published by the group reporting their military campaign in Iraq.
Evaluated and translated by the Institute of War Studies, it divides the attacks into categories and by region, and notes "progress" in terms of numbers and regions, according to the group's strategic aims.
- In 2013, the group boasted of killing 1083 people, up almost a hundred from their annual report the year before
- In 2013 the group said they managed to free "hundreds" of prisoners, whilst the year before they reported being able to free only "dozens"
- The group also said they launched 1047 "targeted attacks" such as improvised explosive devices (IEDs)
There are various reasons for publishing such detailed stats, the ISW said: To show how "centrally distributed resources such as suicide bombers" are used, for internal purposes so more senior members of the central command can monitor how regional sections are performing, and the detail of the report points to an intricate command structure.
One of the main reasons would be to reassure funders that their money was being well spent.
The group have been dubbed "the world's best resourced terror organisation", rivaling the Taliban in Afghanistan, who profit from the heroin trade and the FARC in Columbia, who make a considerable sum from cocaine.
Before the capture of Mosul, Iraqi officials estimated the group had a total of £515 million in cash and assets. After the city was taken over this figure could have jumped by as much as another $1.5 billion, the Guardian reports.
Mosul's central bank contained a lot of cash reserves from Iraq's oil industry, and all of these funds would now be available to the fighters. Since the fall of Mosul, Isis have been attempting to lure residents back to the city with the promise of cheap fuel and water.
The US-based Institute for the Study of War said it was important to consider that the number of attacks could be exaggerated, but concluded, somewhat prophetically back in May this year: