ON THIS DAY - 29 March 1551

On This Day (29 March) in 1551, Lady Mary Dudley, daughter of John Dudley, Earl of Warwick, Lord President of the Regency Council, married Sir Henry Sidney, companion of Edward VI.

'Mary Dudley, Lady Sidney' ?Lavinia Teerlinc, c.1575 ©Victoria and Albert Museum, London

Mary was the eldest daughter of John Dudley, and his wife Jane Guildford; the exact year of her birth is not known, but it is thought that she was born c.1535, making her around 16-years-old at the time of her marriage. John Dudley had been a member of Henry VIII's Privy Council since 1543, on his appointment as Lord High Admiral, and had been one of the sixteen trusted men elected by the dying king in 1547 to form a 'Regency Council', to govern England during the minority of his son and heir, Edward VI. The new king's maternal uncle, Edward Seymour, Earl of Hertford, quickly emerged as the head of the council, taking on the position of 'Lord Protector' and being rewarded with the Dukedom of Somerset. Somerset's Protectorship had brought significant challenges, including the conviction and execution of his younger brother Thomas Seymour, on charges of treason, in addition to a series of uprisings across the country, including in response to the religious reforms being introduced, all of which were initially supported by Dudley, now Earl of Warwick.

'John Dudley, Duke of Northumberland' British School, c.1600 © National Trust Images - Knole

Increased discontent swept throughout the Regency Council, and in October 1549, Seymour had been arrested and imprisoned and taken to the Tower of London, being removed from his position as Lord Protector. In February 1550, his old friend Dudley emerged as the head of the council, taking on the new position of Lord President, which he was to hold throughout the young king's reign. By early 1551, the time of Mary's marriage to Henry Sidney, her father was the most powerful man in England; he had direct access to Edward, had appointed his friends and allies into senior positions within the king's household and government, giving him a significant amount of control and influence.

Since 1550, Dudley's older children had entered into marriages, political alliances, orchestrated by their father: Dudley's eldest son and heir, John, had been married to Seymour's daughter Anne in June 1550, having both political and financial benefits for both families, whilst his next-eldest son Ambrose had also been married to his ward, Anne Whorwood, daughter of Henry VIII's Attorney General.

'Sir Henry Sidney' Unknown Artist, 1573 © National Portrait Gallery, London

Henry Sidney was the son of Sir William Sidney, another member of Henry VIII's Privy Council and Lieutenant of the Tower of London. At the time of his son's birth in 1529, William Sidney was held in high esteem by the king, and so the young Henry was brought up at court, later with the young Prince Edward, (as would young Ambrose and Robert Dudley), whom he would become a close companion to. The alliance between Sidney and Dudley dates back to Henry VIII's reign, and this is possibly when a marriage was first proposed between their children.

The young couple were first married in private at Esher Palace, Surrey, one of Edward VI's royal properties, on 29 March 1551. Two months later, their marriage was "publicly and honourably solemnized" at Ely Place, one of Dudley's London townhouses, located in Holborne, on 17 May 1551.

The marriage appears to have been a successful but challenging one, producing seven children, including poets Sir Philip Sidney and Mary Sidney, Lady Herbert, Countess of Pembroke. They also endured tragedy with the death of three daughters in infancy and childhood. Mary also witnessed the significant fall of her family in July 1553, with the arrest and imprisonment of her parents and five brothers after the attempted coup to place her sister-in-law Lady Jane Grey on the throne, with subsequent execution of her father and brother Guildford. The couple divided their time between Penshurst Place (the Kent estate inherited from Henry's father), London (where Mary was appointed as an Lady of the Privy Chamber), Dublin, Ireland (where Henry was serving as Lord Deputy in Ireland), and Ludlow (where Henry had been appointed as Lord President of Wales). Throughout their marriage, the couple were faced with financial hardships, with Henry having to refuse a Barony, as he could not afford the costs associated with its promotion.