Really not all that surprising.

Via Daily Mail:

British jihadists make up the largest foreign contingent of one of the most violent terrorist groups in Syria, now infamous for beheading, crucifying and stoning to death enemies.

Syrian rebel commander Brigadier-General Abdulellah al-Basheer has urged the UK to send weapons to help fight Sunni Islamist group The Islamic State in Iraq and Syria (ISIS).

Almost two out of three of ISIS’ fighters are foreign-born and have chosen to join a group bent on creating an Islamic state in the war-torn country and Iraq.

The group is so extreme that it has even been denounced by Al Qaeda.

Earlier this month the Foreign Office said it was investigating into reports that two British nationals died fighting for ISIS.

Around 400 Britons are believed to have gone to Syria over the last two years to fight, with an estimated 20 having died.

Last week Mashudur Choudhury, 31, became the first person in the UK to be convicted of terrorist offences in connection with the Syria conflict after he went to the Middle Eastern country with the intention of joining a terrorist training camp last October.

In a letter to The Times, General al-Basheer, chief of staff of the supreme military council, the commanding body of the rebel Free Syrian Army (FSA), which opposes the regime of President Assad, said the ‘majority’ of ISIS fighters were from the UK, with others from France, Germany and Belgium.