Barbara was the sole child and heiress John Gamage of Coity Castle, Glamorgan, and his wife Gwenllian. On the death of her father in September 1584 she was granted by the crown in wardship to Sir Edward Stradling of St Donat's Castle, Glamorgan, until her marriage. Her aunt Margaret, her father's sister, who was the first wife of William Howard, 1st Baron Howard of Effingham, wrote to Stradling in the late 1570s to thank him and his wife Agnes, who was responsible for teaching Barbara to run a household.
Marriage
As an heiress, Barbara Gamage was much sought after in marriage, and at least three of her relations were among her suitors: Thomas Jones of Abermarlis, Sir James Whitney, and Herbert Croft. Lord Burghley, who disapproved of the Stradlings being appointed her guardians, favoured Croft, whose grandfather, Sir James, was controller of her household of Queen Elizabeth I of England; Sir James claimed that the Stradlings had given their written permission for such a marriage. Barbara, when she came of age, was forbidden to contract a marriage without the queen's consent. However, Francis Walsingham, another of the queen's close advisors, had married his daughter to Sir Philip Sidney, and favoured a match between Barbara Gamage and Sir Philip's brother Robert Sidney. The story of their romance was later recorded by one of their children, Mary Sidney, Lady Wroth, in The Countesse of Mountgomeries Urania, published in 1621, the year of her mother's death. On 23 September 1584, she married Robert Sidney in 1616, at St Donat's Castle, the home of her guardian. Although Sidney was the Member of Parliament for Glamorgan, the couple lived chiefly at Baynard's Castle in London and at Penshurst Place in Kent, and the latter house was extended under Barbara's direction, replicating features from her former home at St Donat's.
Sidney's letters to his wife, written when he was away from home on official business, have been published, and contain information about household details as well as major events. Her letters to him have not survived. According to the editor of Ben Jonson's poem "To Penshurst", the "My Lady's Oak" and "Gamage copse" mentioned in the poem are references to Barbara Sidney. According to tradition, she "was taken in travail under an oak in Penshurst Park, which was afterwards called My Lady's Oak ", and it is also said that she liked to feed the deer under the shade of the copse. The forested area became known as "Lady Gamage's Bower".
