The founder of the family was Thomas Mildmay who was a merchant that manned his own stall in Chelmsford market, and then he prospered sufficiently to buy the principal house in the town from Richard Rich in 1527.
Nothing has been discovered about Thomas Mildmay’s early life and education.
Presumably he learnt the rudiments of accountancy and at his father’s prompting he obtained his first post in augmentations through his father’s dealings with Rich, who was the court’s first chancellor.
Jane Mildmay [1764-1857] inherited the Islington estate in 1784.
In 1786 she married Sir Henry Paulet St. John [1764-1808]. He added Mildmay to his name to ensure continuity of the property ownership.
Jane lived for fifty years after the death of her husband and in the 1840’s she leased property to build houses on the estate.
Jane St John-Mildmay sold land to the new railway that was built through the estate. The East and West India Docks and Birmingham Junction Railway opened in 1850 and was renamed The North London Railway in 1853.
Mildmay House became 9 & 10 Newington Green and later became a home for the Pennyfather’s nurses.