An African woman was kept as a slave for four years in the London home of a retired doctor, a court has heard.
Mwanahamisi Mruke, 47, who was flown over from Tanzania in October 2006, was summoned by a bell to carry out chores for Saeeda Khan, 68, around her Harrow house, it is alleged.
A jury at Southwark Crown Court heard Miss Mruke was forced to sleep on the kitchen floor, even after she had an operation on varicose veins in her leg.
They were shown an interview with the Tanzanian in which she described to police her normal working day in which she was expected to wake up at 6am and not go to bed until midnight.
She did cleaning, gardening, cooked meals and accompanied Khan's disabled son on walks, often in the middle of the night, because she wanted to support her 23-year-old daughter through college in her home country.
Miss Mruke said she was paid £120 for her first year's work, just £10 a month, and received no pay for the following three years.
A total of 50,000 Tanzanian shillings (£21) was sent to her daughter each month for two years.
Her mother died during her enslavement, but Miss Mruke said Khan told her she did not have enough money to send her back to Tanzania, the court heard.
She did try to complain, but she was sent a letter from another person in Tanzania to warn her that she must obey Khan, and that if she talked to anyone else her life may be in danger.
Khan, of Whitmore Road, Harrow, north west London, is believed to be one of the first people to stand trial for modern-day slavery.
The pensioner, who denies trafficking Miss Mruke into the UK to exploit her, wore a beige overcoat and a black headscarf as she listened to the evidence from the back of the court, outside of the dock.