WARSAW, July 17 -- The friendship between Britain and Poland is ever stronger, there is no doubt that it will be developed in the future, British Price William read out a letter from Queen Elizabeth II on Monday in Warsaw.

During a reception celebrating the ninety-first birthday of Queen Elizabeth II, Prince William read this letter from his grandmother. She wrote that recounting the history of British-Polish relations, she reminded that they went back a thousand years and were ever stronger.

After reading the letter, Prince William said Britain and Poland have good relations in lots of areas, including diplomatic and cultural, which offers a lot of possibilities. He also said that Polish is the second language most often heard in Britain.

Britain's Prince William and Catherine, Duchess of Cambridge, accompanied by their children, Prince George and Princess Charlotte, began their official visit to Poland on Monday.

The royal couple was welcomed by Polish President Andrzej Duda and first lady in the Presidential Palace. This was followed by a stroll down Krakowskie Przedmiescie Avenue and visit to the Warsaw Uprising Museum.

The Duke and Duchess of Cambridge will furthermore go to Gdansk, northern Poland, on Tuesday, and will hold a private meeting with the Polish presidential couple in Warsaw on Wednesday, after which they will leave for Germany.

The three-day Poland visit is made at the request of the Foreign and Commonwealth Office to help to maintain and strengthen Britain's relations with Europe in the view of Brexit.