A High Court judge is set to decide whether an estranged couple who took part in an Islamic wedding ceremony in a London restaurant are validly married under English law.
Nasreen Akhter, 46, says her 1998 "Islamic faith marriage" to Mohammed Shabaz Khan, also 46, constituted a "valid marriage". Mr Khan disagrees.
Mr Justice Williams is overseeing the case at a trial in the Family Division of the High Court in London.
He began hearing evidence days after the Home Office published an experts' independent review into the application of Sharia law in England and Wales.
Lawyers say his ruling will have implications.
The judge heard evidence from Mrs Akhter, a solicitor who wants a divorce, and Mr Khan, who was involved in a property business and worked in Dubai, on Tuesday.
He is due to analyse legal argument from lawyers on both sides at a follow-up hearing in the near future.
The judge heard that the couple, who have a Pakistani background, had taken part in a "nikah" ceremony at a restaurant in Southall, west London, nearly 20 years ago and lived in Pinner, Middlesex.
Mr Khan said he had operated a property business. He told how a lifestyle involving "maids", "beautiful houses" and a "swimming pool" had come to an end in the wake of the 2008 financial "turmoil".
Mrs Akhter said the nikah ceremony was conducted by an Imam before about 150 guests.
She said Mr Khan had become her "husband" and he had considered her his "wife".
"From my limited understanding of Islam at the time it did comply with all the requirements," she said.
"I saw him as my husband. There was no question in my mind at all."
She added: "He always introduced me as his wife".
Mr Khan wants to block Mrs Akhter's divorce application on the basis that they are "not legally married" under English law and says they are married "under Sharia law only".
Barrister Paula Rhone-Adrien, who is leading Mr Khan's legal team, said issues being considered went to the heart of the understanding of the law of marriage and divorce in British society.
She said the judge's ruling was likely to be "considered in full" by Muslims.
An experts' review into the application of Sharia law was published earlier this month after being commissioned by the Home Office.
Prime Minister Theresa May had asked for a review when she was Home Secretary. She wanted to explore whether Sharia law was being applied in a way that was incompatible with domestic legislation.
A panel of experts, which included an academic and lawyers, said Muslim couples should be required to undergo civil marriages in addition to Muslim ceremonies to bring Islamic marriage legally into line with Christian and Jewish marriage.