Terror group ISIS will march on Rome in its quest to establish an Islamic state from the Middle East across Europe, its self-proclaimed 'caliph' has announced.
In an audio recording Abu Bakr al-Baghdadi called on Muslims to rally to his pan-Islamic, which ISIS now simply calls 'Islamic State'.
"Those who can immigrate to the Islamic State should immigrate, as immigration to the house of Islam is a duty," he said.
Demonstrators chant pro-al-Qaeda-inspired Islamic State of Iraq and the Levant as they carry al-Qaeda flags in front of the provincial government headquarters in Mosul
"Rush O Muslims to your state. It is your state. Syria is not for Syrians and Iraq is not for Iraqis. The land is for the Muslims, all Muslims.
"This is my advice to you. If you hold to it you will conquer Rome and own the world, if Allah wills."
He called not only for fighters, but for "judges and those who have military and managerial and service skills, and doctors and engineers in all fields."
"In this virtuous month or in any other month, there is no deed better than jihad in the path of Allah, so take advantage of this opportunity and walk the path of you righteous predecessors," he added. "So to arms, to arms, soldiers of Islam, fight, fight."
Previous caliphates ruled over large swathes of the Muslim world, from Europe to Asia. The last one, the Ottoman caliphate, was abolished in 1924 in reforms by military leader Mustafa Kemal Atatürk who established modern-day Turkey.
Abu Bakr al-Baghdadi, which is a pseudonym, has picked the name for its resonance with the first caliph in 632, also called Abu Bakr, the first ruler after the death of the Prophet Muhammed.
The Umayyad Caliphate at its greatest extent
The second of the four historical caliphates, known as the Umayyad Caliphate, stretched across the Middle East, North Africa, through Persia and into modern day Pakistan and included most of Spain, the fifth largest empire the world has ever seen.
But contrary to the violent and oppressive laws enacted in Baghdadi's new "Islamic state", the Umayyad Caliphate was culturally tolerant and diverse. Jews and Arabs had cordial relations, with Jewish stonemasons helping to build the Great Mosque in Cordoba. Although not actively persecuted, Jews and Christians were taxed a special amount called a jizya. Emphasis was placed on learning, with major advances in science, mathematics and philosophy made during the Caliphate.
Baghdadi's bombastic and rather unfeasible boast that he will conquer not only Spain but also Rome comes as photographs show a large weapon being paraded on the back on a lorry in the Syrian city of Raqqa - the proclaimed capital of the new caliphate.
On social media, the weapon is being widely touted as a Scud missile, though the Daily Mail reported that experts analysing the images said the weapon is almost certainly inoperable and highly unlikely to pose a threat
ISIS' rallying call to Muslims worldwide may have less of an effect than they might hope, according to the latest Pew Research, which found support for radical groups is on the slide, according to a poll released on Tuesday, conducted prior to the Islamic State advances.
Interviewing more than 14,200 people in 14 countries, the researchers found extremist groups such as al-Qaeda, Hezbollah, Boko Haram and Hamas are also losing support. Support for suicide bombing of civilian targets has also dropped significantly in the past decade.
In Lebanon, which borders Syria, 92% said they were worried about Islamic extremism, up 11 points from 2013, and concern has also significantly risen in Jordan and Turkey.
An overwhelming majority of Nigerians (79%) were against Boko Haram,, while 59% of Pakistanis said they opposed the Taliban. Just over half of Palestinians said they distrusted Hamas, rising to 63% in the Gaza Strip, which is controlled by the party.
Al Qaeda gets negative marks in all 14 countries surveyed. Strong majorities in most countries have unfavorable opinions of the group, founded by Osama bin Laden more than a quarter century ago.