Kate, the Duchess of Cambridge, sparkled in her late mother-in-law's tiara at the lavish state banquet held in President Donald Trump's honor at Buckingham Palace on Monday evening.

Kate wore the Lover's Knot tiara, which was beloved by Princess Diana. The tiara was created by Queen Elizabeth's grandmother, Queen Mary, in 1913.

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PHOTO: Kate, the Duchess of Cambridge and United States Secretary of the Treasury, Steven Mnuchin arrive through the East Gallery ahead of the State Banquet at Buckingham Palace in London, June 3, 2019.
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Kate, the Duchess of Cambridge and United States Secretary of the Treasury, Steven Mnuchin arrive through the East Gallery ahead of the State Banquet at Buckingham Palace in London, June 3, 2019.
(MORE: Duchess Kate gives Queen Elizabeth II a tour of her Chelsea Flower Show garden)

She completed her glamorous look with a white Alexander McQueen gown -- the luxury fashion house that designed the wedding dress she wore back in 2011 -- and diamond and sapphire earrings she borrowed from Queen Elizabeth II herself.

PHOTO: Camilla, Duchess of Cornwall and Robert Wood Johnson, the United States Ambassador to the United Kingdom arrive through the East Gallery for a State Banquet at Buckingham Palace, June 3, 2019, in London.
Victoria Jones/Getty Images
Camilla, Duchess of Cornwall and Robert Wood Johnson, the United States Ambassador to the United Kingdom arrive through the East Gallery for a State Banquet at Buckingham Palace, June 3, 2019, in London.
(MORE: 'Fab Four' Prince William, Prince Harry, Duchess Kate and Duchess Meghan join Queen Elizabeth to celebrate Prince Charles' anniversary)

Camilla, the Duchess of Cornwall, also attended the glitzy affair, donning a cream-colored gown by Bruce Oldfield.

PHOTO: President Donald Trump, Queen Elizabeth, first lady Melania Trump, Prince Charles and Camilla, the Duchess of Cornwall pose for the media ahead of the State Banquet at Buckingham Palace in London, June 3, 2019.
Alastair Grant/AP
President Donald Trump, Queen Elizabeth, first lady Melania Trump, Prince Charles and Camilla, the Duchess of Cornwall pose for the media ahead of the State Banquet at Buckingham Palace in London, June 3, 2019.

The queen wore a white gown by her personal dressmaker Angela Kelly that featured crystal centered daisies, and paired it with a burmese ruby and diamond tiara.

Although the president was visiting, the American Duchess Meghan was absent from the event as she is on maternity leave after giving birth to her first child last month.

PHOTO: Catherine, the Duchess of Cambridge arrives at Buckingham Palace for the State visit of President Trump and the first lady, June 3, 2019.
Andrew Parsons/i-Images/Polaris
Catherine, the Duchess of Cambridge arrives at Buckingham Palace for the State visit of President Trump and the first lady, June 3, 2019.