Britain's Queen Elizabeth has bought a flat in Chicago.

Queen Elizabeth

Queen Elizabeth

The 89-year-old royal - who became the longest reigning monarch last week - has snapped up a lavish apartment on the 26th floor of the 44-storey building at 360 E. Randolph Street - also known as The Buckingham - in Illinois.

Her Majesty, who is also the Queen of Canada, isn't planning to stay in her new abode but forked out for the property for Canadian Consul General Roy Norton to live in.

It's not known how much the Queen paid for the apartment but according to the Crain's Chicago Business, the lavish space was officially signed over to her late last month.

Meanwhile, Elizabeth became Britain's longest-reigning monarch last Wednesday (09.09.15) after she surpass her great-great-grandmother Queen Victoria, who served the country for 63 years and seven months.

Acknowledging her record-breaking reign, the queen admitted: "It is one to which I have never aspired".

But she added at the ceremony: "Inevitably a long life can pass by many milestones - my own is no exception - but I thank you all and the many others at home and overseas for your touching messages of great kindness."

The exact moment the royal passed Victoria's milestone is not known as there is no precise time of death for her father, George VI - who died in the early hours of February 6 1952.