Britain’s Supreme Court will hear the case of Shamima Begum, the 21-year-old who had her British citizenship removed after she travelled to Syria to marry an Islamic State guerilla.

Then-Home Secretary Sajid Javid removed her citizenship in February 2019 due to national security concerns. Under observed international law, it is illegal to render a person stateless; however, the British government said that it was able to revoke British-born Begum’s citizenship due to her parents being from Bangladesh. Bangladesh’s minister of state for foreign affairs has declared that Begum would neither be granted citizenship nor allowed into the country.

The Begums began legal action, and in July 2020, the Court of Appeal ruled that the ISIS member should be allowed to return to the UK to challenge the removal of her citizenship in person. However, that same month the government won the right to take the decision to the Supreme Court, which will hear the case, remotely, for the next two days.

Ms Begum was 15 when she and two other east London schoolgirls Kadiza Sultana and Amira Abase flew to Turkey and travelled on to Islamic State-controlled Syria to become ISIS brides.

The underaged teen ‘married’ the jihadist Yago Riedijk ten days after she arrived in Syria, the Dutch Muslim convert being 13 years her senior. Between that time and her discovery at a Kurdish-run refugee camp in Syria in February 2019 by The Times, she had given birth twice and was nine months pregnant. All three of her young children have since died.

It was interviews and subsequent reports from the Kurdish camp that revealed Ms Begum’s life under the Caliphate. Begum was being held at the Al Roj camp along with other ISIS brides and their children. Speaking to the newspaper of record, she revealed that she did not regret joining the terrorist group but that she did not have “high hopes” the Caliphate would survive.

She had also claimed that life under the oppressive Islamist regime was “normal” and “the one I wanted”. Describing the first time she saw a severed head in a bin, she said that it “didn’t faze me at all”.

While claiming to be nothing more than a housewife, sources speaking to The Telegraph in April 2019 alleged that, rather, Begum had “earned a reputation as a strict ‘enforcer'” for Islamic State’s morality police, carrying a Kalashnikov rifle while imposing sharia dress codes on women.  A senior intelligence source told the Daily Mail that same month that “She was involved and her former comrades have grassed her. She was literally stitching the [suicide] vests, stitching them into the vests.”

When made aware last year that Home Secretary Javid had removed her British citizenship, Begum told ITV that “He [Javid] has no proof that I’m a threat. Other than I was in ISIS, but that’s it.”

Also on Monday, the Special Immigration Appeals Commission will hear the cases of two other women and one man who are challenging the government’s decision to revoke their British citizenship, claiming that they were rendered stateless.

Following the Court of Appeal’s ruling in favour of Ms Begum, The Henry Jackson Society warned that as many as 150 jihadists could attempt legal returns to the UK to challenge their citizenship revocation.

Once in the UK, these dozens of terrorists will be near impossible to deport even if courts eventually side with the government. The European Convention of Human Rights forbids deportations if a person is at risk of execution or ill-treatment, with many countries in the developing world handing out harsh punishments to terrorists.