The island's original Irish name was Inishmacadurn. It sits in the maze of small islands between Burtonport on the mainland and Arranmore offshore, in the area of West Donegal called the Rosses. It is small, mostly granite, exposed to the Atlantic. The local population had used it for grazing and occasional shelter. Before Conyngham, no one had ever tried to build a town here. The British administration in the late eighteenth century was actively encouraging fisheries development on the Irish west coast, partly as economic policy and partly to provide a more legible alternative to the smuggling that flourished in these channels. Conyngham, a Donegal landowner with significant political connections, was a champion of the fisheries scheme. He poured private money into Rutland.

The main street of the planned town was called Tarent Street, built in 1789. Photographs survive of what remains of it: stone buildings, walls partly tumbled, foundations visible in the turf. The town was designed on a grid, with separate residential and commercial blocks, in the manner of late-Georgian planning. The fish-landing facility was substantial. Salt-houses, curing sheds, processing rooms were all built to standards far above what the local economy could normally support. The schoolmaster was paid. The post office served the surrounding islands. For a brief period in the 1790s, Rutland was a real town, the rare experiment in late-eighteenth century planned urbanism actually built in one of the most remote corners of Ireland.

Atlantic herring stocks are notoriously variable. The shoals that had brought boats in to Rutland's pier through the 1780s and early 1790s simply ceased to appear in the same numbers. By the early 1800s, the catches were a fraction of what the town had been built for. The processing facilities went idle. The fishermen moved to other ports or other occupations. The shops closed. The school continued for a while because the surrounding islands still had children. The post office served a thinning population. The town slowly emptied. Some residents stayed, raising families through the nineteenth century in houses that had been built for a busier reality. The island remained inhabited continuously into the 1960s. The Famine, that great agent of Donegal depopulation, swept through here too in the 1840s. The town never recovered.

Mains electricity reached Rutland Island in 1957, but not for its residents. The cable ran across Rutland to continue on to Arranmore, where the larger inhabited island was being electrified as part of the Rural Electrification Scheme. Rutland received electricity because the engineering required it as a stepping stone. The remaining holiday cottages on Rutland have power. They have never had piped water. The remaining houses are all holiday homes; the year-round population is officially zero. The wider Rutland electoral district, which on paper is named after the island but includes Burtonport on the mainland and a number of surrounding islands, had 1,428 residents in the 2006 census. The island itself contributes none of them.

In the first decade of the 2000s, Rutland Island experienced a small holiday-home boom. Several new cottages were built, joining the older converted residences, all serving as summer retreats for owners from the mainland and from farther afield. The island has no ferry service. Owners reach their cottages by private boat from Burtonport or from Arranmore. The badgers of Rutland have been recorded by Irish wildlife surveyors, with notes that their diet shows evidence of being poor, the inevitable consequence of an island this small and exposed. Foxes are also present. Marine algae of the Rutland South Channel have been catalogued in scientific surveys, with the long Latin names that botanists give to seaweeds. Ruins of Conyngham's town are still visible. Tarent Street is still walkable, in places. The herring did not come back. The badgers continue to forage. The island continues to exist as a quiet kind of monument to a busy idea.