Kate's three great-uncles - brothers Maurice, Lionel and Francis Lupton - were all killed in action during the conflict, leaving behind two sisters - including her great-grandmother, Olive Middleton. Their father had no surviving sons.
The three young men came from a wealthy family who had made their fortune in wool manufacturing. They owned Whitehall Mills and they lived at Potternewton Hall, near Chapel Allerton. The Luptons had owned the estate since the early 1800s, and St Martin's Church on Chapeltown Road was built on their land.
The Duchess is expected to view letters written by Maurice, who died in 1915 aged 28, Lionel, who died in 1916 aged 24, and Francis, who was killed in 1917 aged 31, during her visit to the London museum.
A telegram sent to Olive by her husband, Lieutenant Richard Middleton, informing her of Francis's death has survived. Olive herself worked as a nurse with the Voluntary Aid Detachment during the war. Her son Peter, who became a World War Two flying ace, is the father of Michael Middleton, Kate's father.
Michael Middleton was born in Leeds in 1949, and grew up in Moortown. His family were well-known solicitors in in the city who ran their own firm, Middleton and Sons. His father Peter was an airline pilot who once flew alongside Prince Philip, while his grandfather Richard was one of the founders of the Yorkshire Symphony Orchestra.
It is through Richard's marriage that the Middletons became allied to the Luptons, whose name lives on in modern Leeds through their various philanthropic legacies. The wool barons owned the Potternewton Hall estate, which was later sold for housing and encompasses parts of Chapeltown. Olive was born in a property on nearby Newton Grove, and grew up in a house called Rockland.
Olive worked as a nurse in the military hospital at Gledhow Hall, near Chapel Allerton, during World War One. After her brothers' deaths she inherited her family's carefully-curated trust funds. Potternewton Hall, the family mansion, was demolished before World War Two and the land sold for housing development.
After they married, Olive and Richard lived in a house called Fieldhead in Roundhay, which passed to Richard and their children after her death in 1936. They also owned another Roundhay property called Linden.