Magdalene Hall was one of six children of Sir James Hall, 4th baronet of Dunglass, a wealthy MP and eminent scientist, and his wife Lady Helen Hamilton Douglas. Her brother Basil Hall grew up to be a well-known Royal Navy officer, explorer, author, and friend of Sir Walter Scott. The Hall family lived in Edinburgh and on the 9,000-acre Dunglass estate near Dunbar. In 1815, after a whirlwind romance, Magdalene married Col. Sir William Howe DeLancey (also spelled Delancey, De Lancy and Delancy), a veteran of the Napoleonic wars and the Duke of Wellington's chief of staff. Having been married only a few weeks, in June Lady DeLancey accompanied her husband and the Anglo-Allied Army to Brussels to engage the Emperor Napoleon again after his return from Elba. It was uncommon, though not unknown, for British wives to follow their husbands to war. She took up residence in the house of the comte de Lannoy at the Impasse du Parc, close to Wellington's house. Although the DeLanceys were invited to the Duchess of Richmond’s famous ball on the night of June 15, they seem not to have attended. Sir William was mortally wounded by a cannonball at the Battle of Waterloo, and Magdalene nursed him devotedly until his death 10 days later. The following year, Lady DeLancey wrote a heartrending Narrative of the event for family and friends that was shared and avidly read by many in manuscript form, including Wellington and Sir Walter Scott, who admired the work, as did Charles Dickens later. First published in abridged form in London in 1888, the work was republished in 1906 in Britain and the USA under the title A Week at Waterloo in June 1815. Magdalene Lady DeLancey married again in 1817 to Capt. Henry Harvey of the Madras Infantry, and died in 1822 after giving birth to their third child. In the 1990s, historian David M.O. Miller researched the whole history of Lady DeLancey's Narrative, unearthing a trunk in the possession of her great-great-great grandson containing what appeared to be the original version in blue velvet binding with her initials embossed in gold. This led to his writing the book Lady DeLancey at Waterloo: A Story of Duty and Devotion, published in 2000.