The collection consists of letterbooks from 1866, and 1871 to 1874; diaries, 1871 to 1913; and loose papers, 1871 to 1874. There is a volume of transcripts of the more important documents, with Loraine's accounts of the various incidents in his career. There are also some letters to Loraine's son, Sir Percy L. Loraine (1880-1961), and some pamphlets in Spanish.

Administrative / biographical background
Loraine was born at Fawdon in Northumberland in 1838. He succeeded to the baronetcy of Kirkharle on the death of his father in 1852 and in the same year entered the Navy. He was promoted to lieutenant in 1858 and served in the Mediterranean. In 1864 he was appointed flag-lieutenant to Rear-Admiral the Hon. Joseph Denman, commander-in-chief on the Pacific station. In 1866 he was acting commander of HMS MUTINE during the hostilities between Spain and her former colonies, Peru and Chile, being promoted to commander in 1867. From 1871 to 1874 Loraine commanded HMS NIOBE on the North America and West Indies station. He spent part of this time engaged in fishery protection off the Canadian coast and the remainder in the West Indies. In March 1873 the NIOBE was sent to Santo Domingo to support the diplomatic status of the British representatives there over a case of political asylum. In June of that year, Loraine was sent to protect British interests in Omoa, Honduras, against the local military commander and representative of the provisional government. In November he was ordered to intervene in the VIRGINIUS affair. The VIRGINIUS was an American ship, owned by Cuban exiles. She had been captured by Spanish forces and taken to Santiago de Cuba where the officers and crew were summarily executed and the lives of the passengers threatened. Loraine' s intervention led to the release of the ship and passengers. He was promoted to captain in 1874 and retired from active service in the following year, though he did command HMS GORGON for a few months in 1878. He was promoted to rear-admiral on the retired list in 1889.