When the extremist group Isis (now known as Islamic State or IS) declared a caliphate taking in parts of Syria and Iraq it reignited a debate over the role of an Islamic state.
For many a caliphate is a political leadership, others a spiritual figurehead, and for some a combination of the two.
"What we're seeing being carried out against helpless civilians like the Yazidis and other groups isn't what an Islamic state is about," says Yasmin Khatun, a journalist from London.
.... Saif holds the view that would be considered the most extreme of this group - he supports the Islamic State caliphate despite their violence and thinks that the group's leader Abu Bakr al-Baghdadi is a valid caliph.
"The caliphate for me is a government, a state which rules by the Qur'an and Sunnah (practices of the Prophet Muhammad), and those laws are over Muslims and non-Muslims. [BBC] Read more
