through their company Ellerman Investments. They spent eight years and £40 million restoring it to its former grandeur. Prince Charles and Camilla Parker-Bowles made their first public appearance together at the Ritz, as they left a birthday party for Parker-Bowles' sister. The couple returned to the hotel in November 2002 for the Prince's birthday party attended by Queen Elizabeth II and Prince Philip. In 2002, the Ritz became the first hotel to receive the Royal Warrant from the Prince of Wales for banqueting and catering services. The Ritz acquired the adjoining Wimbourne House in 2005. On 27 January 2007, around 300 people were evacuated to the nearby May Fair Hotel following a fire alarm in the hotel. No one was hurt in the blaze, which started in the basement casino kitchen's extraction vents. The Ritz casino only suffered "minor damage". Former British Prime Minister Margaret Thatcher was convalescing at the Ritz when she died following a stroke on 8 April 2013. There has been criticism because the Ritz has not paid any corporation tax since being taken over by the Barclay twins. The accounts indicate that the profitable hotel uses a series of tax reliefs to reduce its corporation tax to zero. David Barclay’s son, Aidan, has stated that the company abides by UK law. In March 2020, it was sold to a Qatari investor. Architecture Authors Montgomery-Massingberd and Watkin describe the Ritz as "the product of one of those near miraculous convergences of civilised patron and architects and craftsmen of genius working together in complete harmony both with each other and with the social and architectural fashions of the day. The building has been regarded as a masterpiece from the day it was finished..." Both of the architects, Charles Mewès and Arthur J. Davis, were educated at the prestigious École des Beaux-Arts in Paris, and the education which they received is clear in the design of the buildings, particularly the Renaissance influence, delivering "an authentic fabric of traditional French classicism". Mewès had previously designed the Hotel Ritz of Paris for Cesar in 1897–8, after which he met Arthur Davis, and began working together preparing designs for the Grand Petit Palais in the Paris Exhibition of 1900. Both architects worked on the plans for the London Ritz in 1904–5. According to Montgomery-Massingberd and Watkin the exterior is both structurally and visually Franco-American in influence with little trace of English architecture.