When the Germans occupied Alderney in 1940, the entire civilian population was evacuated. When they were allowed back in late 1945, much of the island's documentary record was gone - destroyed, scattered, or seized. The museum opened first in 1966, in the basement of the Island Hall, run and funded by the Alderney Society. The basement filled almost immediately. The States of Alderney offered the old schoolhouse at what they called a peppercorn rent - a legal term for a fee so small it might as well be a single peppercorn - and volunteers refurbished the building for a formal opening in 1970. The collection is what an island archive becomes when it must also be the island's library and warehouse and lost-and-found: 1940 census papers, cinerary urns, dulcie cups, an 1852 lithograph of the breakwater, church and government documents, baptism registers reaching back to 1662, land registers, cemetery registers, and curry powder bottles.

Gallery 2 holds the museum's most striking collection: artefacts from an Elizabethan shipwreck found in Alderney's waters. Cannonballs. A breastplate. A helmet. Tobacco pipes. The wreck is significant enough that other museums borrow from it - in 2009, pieces travelled from St Anne to the Guernsey Museums in Saint Peter Port for a six-month loan. The objects belong to a moment when Alderney's strategic position between England and France was already centuries old, the rocks around its coast already collecting hulls. A breastplate raised from a wreck is a particular kind of artefact: it once shaped itself to a specific human chest, and someone wore it the day the ship went down.

The Main Gallery, the Maritime Gallery, the Natural History Room, and the upstairs Temporary Exhibition Gallery rotate the rest of the holdings. Rare island maps, plans and charts. Lists of every British regiment stationed in Alderney since 1732. Old court records. Recent temporary exhibitions have included Andy Goldsworthy's Alderney Stones Project - the British land artist's series of clay-and-stone works installed around the island - alongside the 1850 sketches of Sophia Guille and architectural plans of the Victorian fortifications pulled from the National Archives at Kew. The mix is unembarrassed by its own range: an island museum on an island that has been Iron Age settlement, Roman outpost, French parish, Crown dependency, fortress, prison, and home, all at once.

In 1993 the museum was officially fully registered with the Museums, Libraries and Archives Council. In 1999 it received the Museums and Galleries Gulbenkian Award for 'most outstanding achievement' - presented by Prince Charles. For a museum running on a peppercorn rent and the labour of an island society, that is not nothing. The collection it holds is sometimes called modest. It is not. It is the entire surviving documentary memory of a place that was nearly erased from its own records inside living memory, plus the cannonballs of an Elizabethan ship. What the Alderney Society Museum demonstrates is something most national institutions can take for granted: that having a place to keep your own history is itself a kind of survival.