For sale: a £3.15m flat in Princess Diana's Coleherne Court

Before she became the Princess of Wales, Lady Diana Spencer took a brief turn, aged 18, as a landlady.

Her American great-grandmother had left her a princely sum of £50,000, which Lady Diana used as a deposit on a three-bedroom flat in Coleherne Court in 1979.

The red brick mansion block in South Kensington, west London, had grand communal gardens and a waiting list. “Debs’ mothers used to put their daughters there while they were learning how to do shorthand or work in a nursery before getting married,” wrote Tina Brown, in her biography, The Diana Chronicles.

Lady Diana let out her spare rooms to three other friends. But though she collected rent (£18 per week per person), she was an uncommon type of landlady.

She reportedly kept a sign on her door that read “chief chick” and was obsessed with the washing up. “She put herself in charge of clean-up duty, and was known to rise before a meal was finished to clear the table rather than endure the sight of dirty dishes,” wrote Brown.

Her sister, Sarah Spencer, somewhat took advantage, paying Lady Diana a pound an hour to clean her own apartment.

The following year, Lady Diana started going out with Prince Charles. The press descended, desperate to find a scandal. But Lady Diana was a homebird. “The naughtiest film she’d ever seen was La Cage aux Folles! She preferred hot vegetables to the fashionable insalata di radicchio!” wrote Brown.

After Prince Charles proposed in 1981, Coleherne Court suddenly became “the most famous address in Britain”, wrote Andrew Morton, another Diana biographer. The mansion block came under full siege by photographers and journalists. Lady Diana’s mother sold the flat later that year.

Today, residents of the Edwardian block are protected by CCTV and a 24-hour porter service. Another three-bedroom apartment is for sale with Marsh & Parsons estate agents. But these days Lady Diana’s £50,000 would not go far towards a deposit. The price tag is £3.15m.