Henry was the son and heir of Edmund de Lacy, Baron of Pontefract (c. 1230–1258) (eldest son and heir apparent of John de Lacy, Earl of Lincoln (c. 1192–1240) and his wife Margaret de Quincy suo jure Countess of Lincoln (c. 1206–1266)) by his wife Alice of Saluzzo, a Savoyard noblewoman descended from Amadeus IV, Count of Savoy, of the Royal House of Savoy.

Henry's father died in 1258 when he was a young child aged about 7, and he went into wardship, which was re-purchased by his mother, with the help of his grandmother.

As his father had predeceased his own mother, suo jure the Countess of Lincoln, Henry became her heir when she died in 1266, when he was aged 15 and still in wardship.

In 1258, he inherited from his father the titles and offices Baron of Pontefract, Baron of Halton and hereditary Constable of Chester and in about 1266 from his paternal grandmother, Margaret de Quincy, he inherited lands and titles including Earl of Lincoln.

[15] He died at Lincoln's Inn, his City of London townhouse, and was buried in nearby St Paul's Cathedral.

A modern monument in the crypt lists De Lacy among the important graves lost.