Sir Walter Mildmay was educated at Cambridge and became an important figure in royal court proceedings and as an MP. In 1553, in the first year of the reign of Queen Mary, Mildmay was elected MP for Peterborough, having recently gained Apethorpe Hall (now Palace). He was a good friend of William Cecil of Burghley (who had not started building Burghley House yet) and he appears to also have been a good friend of Sir William Fitzwilliam II who had inherited his family estate at Milton and was a fellow MP for Peterborough in 1553; his daughter Winifred married Sir William’s son, also called William. He was also involved in the life and death of Mary Queen of Scots, visiting her with Cecil at Chatsworth and at nearby Fotheringhay, shortly before her execution.
Mildmay gained Apethorpe in 1551 after swapping lands he owned with King Edward VI, Apethorpe having been owned by Henry VIII. Queen Elizabeth I visited Mildmay there in 1562, with an engraving left on a chimney breast to commemorate the occasion, visiting twice more after that. We can also imagine rousing conversations between Mildmay, Cecil, Fitzwilliam and other Tudor dignitaries in some of the Tudor parts of Apethorpe that still stand today. The atmospheric Chapel and Hall are two very fine features of the original Tudor house that remain and can be viewed on guided tours of the house in the summer months with English Heritage.
References:
M. R. P., Fitzwilliam, William (c. 1550-1618), of Dogsthorpe and Milton Northants, The History of Parliament Online, <historyofparliamentonline.org> [accessed 11 February 2021].
S. M. Thorpe and R. J. W. Swales, Mildmay, Walter (by 1523-89), of Apethorpe Northants. and London, The History of Parliament Online, <historyofparliamentonline.org> [accessed 11 February 2021].
Apethorpe Palace, Wikipedia (2021) <en.wikipedia.org/wiki/Apethorpe_Palace> [accessed 11 February 2021].
Walter Mildmay, Wikipedia (2020) <en.wikipedia.org/wiki/Walter_Mildmay> [accessed 11 February 2021].
Image: Paul van Somer I, Public domain, via Wikimedia Commons