The Farne Islands are a group of fifteen to twenty islands (depending on the state of the tide) lying some 2.5-7.5 km (1 1/2-4 3/4 miles) off the coast of Northumberland. Divided into two groups, the main islands in the Inner Group are Inner Farne, Knoxes Reef and the East and West Wideopens (all joined together on very low tides) and (somewhat separated) the Megstone; the main islands in the Outer Group are Staple Island, the Brownsman, North and South Wamses, Big Harcar and the Longstone. The two groups are separated by Staple Sound.

Longstone Rock lies about 9.7 km (6 miles) from the mainland on the westernmost side of the reef. Vegetation is very scanty being predominantly matgrass. The Lighthouse was built and designed by Joseph Nelson in 1826, and was originally called the Outer Farne lighthouse. The site has a long history showing the need for a light, prior to the construction of the lighthouse.  A light was requested for these islands by Sir John Clayton in the late 17th century and by Captain J. Blackett in 1755. Unfortunately both were rejected as the Elder Brethren of Trinity House were unable to obtain the consent of the affected parties to pay a toll for the maintenance of the light.

However, in 1826 it was found essential for the welfare of shipping off the Northumberland coast to construct a lighthouse in the Farne Group on the Longstone Rock. Designed and built by Joseph Nelson, it is a red and white circular tower built of rough stone with iron railings around the lantern gallery. The light originally came from Argand lamps with twelve burners, parabolic reflectors 53 cm (21 in) in diameter and 23 cm (9 in) deep and a catadioptric optical apparatus. The cost of the Lighthouse and the dwellings was approximately £4,771, the lantern alone costing £1,441.

The island was isolated and bleak, with storms frequently so bad that waves covered the living quarters, forcing the family to take refuge in the upper rooms. The lighthouse is most famous for the night in September 1838 when the steamer 'Forfarshire', bound from Hull to Dundee, went aground on Hawkers Rocks, about a mile from the Lighthouse. Forty three people were drowned as the stern portion of the vessel split off and was carried away in the storm. The forepart, to which clung the survivors, remained fast on the rocks. At daybreak William Darling, the keeper, and the fishermen ashore saw the wreck, but the waves were beating against the rocks so much that the fishermen thought it impossible to attempt a rescue and even Darling hesitated. He was finally persuaded to make the attempt by his daughter, with her as the second hand in the small lighthouse boat.

After a terrific struggle, they brought back four men and one woman in their frail open boat and later a further four survivors. All nine had to be accommodated and fed at the lighthouse for two days until the storm abated and they could be taken to the mainland. This gallant action made Grace Darling and her father famous. The Royal Humane Society voted them its gold medal, the Government made them a grant and a public subscription was organised.

Major alterations were made to the Lighthouse in 1952 and the light was converted to electricity. The lighthouse was converted to automatic operation in September 1990 and is now monitored from the Trinity House Operations Control Centre at Harwich.