Lucius O'Callaghan (1877-1954) was born on 18 August 1877 in Dublin. He was educated at the Catholic University School and Blackrock College after which he became a pupil in the office of his father, the architect James Joseph O’Callaghan. After working for a number of well known architects he set up in independent practice in 1903 and later entered into a partnership with Louis Giron and James Henry Webb. O'Callaghan was a connoisseur and collector of paintings, particularly seventeenth century Dutch works, and of antique furniture and porcelain. He was a member of the RHA, an ex-President of the Royal Institute of Architects of Ireland and In 1917 was appointed as a member of the Board of the National Gallery of Ireland for a five year term. In November 1923 he was appointed Director of the NGI, having made it clear in his application for the post that, if appointed, he should be allowed to continue to practise as an architect. He conducted the Gallery's affairs quietly and efficiently until June 1927, when he resigned on account of his architectural commitments. O'Callaghan died on 5 December 1954 leaving Louis Giron to carry on the practice.