One of Isis’s most senior recruiters lived in Britain and married his British wife in a Yorkshire town hall.

John Georgelas, an American, wed Joya Choudhury, a young Briton of Bengali descent, in Rochdale in 2004 when they were both 19. They had met online after Georgelas converted to Islam.

The American, who uses the Arabic name Yahya Abu Hassan, is now believed to be the most senior westerner in Isis.

He is the son of a former US Air Force doctor and the grandson of an American Second World War veteran but was revealed last month to have become a senior Isis figure who has urged followers to carry out terrorist attacks in the west and lured scores of young Britons to join the terrorist group in Iraq and Syria.

Georgelas spent some of his childhood in Britain, living near Cambridge while his father was serving in the UK. He converted to Islam in 2001, soon after the 9/11 attacks, having befriended a group of Muslim students at his college in Texas.

His wife, Choudhury, is believed to have been radicalised during her A-level studies at a college in East London. She became friends with a group of Algerian Muslims who dressed conservatively and followed a strict interpretation of Islam.

As her new friends began to get married, Choudhury met Georgelas on a Muslim dating website in 2003, according to the Sunday Times.

He travelled to the UK and the pair lived in a number of British towns. It was in London that they became involved with radical Islamic preachers. Some reports suggest they were connected to Anjem Choudary, the jihadi cleric who is now behind bars after being convicted of terrorism offences for supporting Isis.

The couple moved to the US after the birth of their first son. Georgelas began working at an internet hosting company in Dallas, Texas, but was found to be using the organisation as cover for helping online al-Qaeda sympathisers. In 2006 he was sentenced to almost three years in prison for hacking into the website of the American Israel Public Affairs Committee (Aipac).

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On his release, Georgelas took a second wife – a Jamaican friend of Choudhury’s who had converted to Islam – but the marriage did not last.

Fearing they were being tracked by the FBI, Georgelas and Choudhury moved to Egypt in 2011. Two years later they were in Syria, with the American having established a growing reputation in jihadi circles.

By this time the couple had three children and Choudhury was pregnant with their fourth. Nevertheless, they entered the country as it was being engulfed by civil war.

Choudhury and her children soon became malnourished and seriously ill. She reportedly decided she needed to get out.

A source told the Times: “She has behaved selfishly for virtually all of her life. Now, finally, she decided to put her children before herself.”

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She travelled to Turkey and then back to London, while Georgelas stayed in Syria and soon committed himself to the newly-formed Isis. Unhappy in Britain, the mother-of-four returned to America and settled close to Georgelas’ parents, who now help look after the couple’s four children.

​Choudhury filed for divorce from her husband in 2014 – the year Isis was formed. Georgelas, meanwhile, has rapidly risen up the organisation’s ranks to become a senior recruiter and propagandist.

Last year he wrote an article calling for Sajid Javid, the UK Secretary of State for Communities and Local Government, and Baroness Warsi, the former Conservative Party chairwoman, to be killed because they are “apostates”. He is believed to be responsible for recruiting scores of young westerns to the jihadi group.