It had been inhabited at least since the Neolithic period, but Eigg nearly lost her people two decades ago when a population that had stood at 500 two centuries earlier, was down to the last 64.

However today the islanders will be joined by friends and guests to mark the 20th anniversary of the community buyout of the island for £1.5m, which reversed the chronic depopulation which had blighted the island.

Since 1997 many of the obstacles to island life under previous private owners, have been removed. Tenants have been given security of tenure, homes have been modernised, new houses built, businesses started, woodland made productive. But perhaps the most impressive achievement has been the development of an award winning green energy grid - a mix of hydro, wind turbines and a photovoltaic array which ended islanders' reliance on diesel generators.

With such enterprise the population has risen from 64 to 105, a near 65 per cent increase.

But things could have been so different for Eigg, originally a Clanranald MacDonald island which was sold nine times under private ownership. Its previous long time controversial laird Keith Schellenberg, who had threatened some with eviction, sold the island to the German artist Marling Eckhard-Maruma for £1.6m in 1995. Maruma promptly sold off the island’s cattle, but not before he had taken out loans against the island at punitive rates of interest in Hong Kong and Liechtenstein. Eigg had become a pawn in a game of international land speculation.

Meanwhile the lottery-financed Heritage Memorial Fund refused to assist a buyout if the local people were to control the island. Apparently, the islanders were not to be trusted to look after their own future. Yet a year earlier the same body had given the Churchill family £13.25m for the retrieval of its papers.

To get round the problem, Simon Fraser, the Stornoway solicitor who had masterminded the ground breaking Assynt Crofters' buyout in 1993, came up with a solution – the Isle of Eigg Heritage Trust a company limited by guarantee with a membership of three organisations: the island residents' association, the Scottish Wildlife Trust and the Highland Council. The trust survives today.

But in the end the islanders’ public appeal attracted 10,000 donations from across the land and beyond. These ranged from children sending their pocket money to the £750,000 (circa £900,000 with gift aid tax relief) from an anonymous benefactress in the north of England.

The only one who definitely knows her identity is Maggie Fyffe, IEHT secretary and driving force. She has always refused to divulge her name, but was in touch with her last week.

Looking back Ms Fyffe said “Buying our island started out as a pipe dream, but when the community began to realise the only way to provide a secure future that gave the residents a voice in how the developed, was to do it ourselves.

“Make no mistake, it isn’t a decision to be taken lightly. There’s a huge amount of work involved and Eigg’s success is undoubtedly due in part to the many hours put in by volunteers. Has it been worth it? Most definitely!

She said with young people returning to raise their own families on the island and businesses starting up, there was a feeling of security. “It’s like night and day.”

A local craftsman is working on a bench in memory of Simon Fraser , who died last year. As well as being the IEHT’s lawyer, he was also its first chairman. His widow Ann and daughter Cara Martin will be guests at today's celebrations.

Dr Michael Foxley the former leader of the Highland Council who had long been active in Eigg’s cause, said it was a fitting gesture for his friend.

“Simon loved Eigg. Without his professionalism and tactical wit, it is it doubtful Eigg would have succeeded. Or that there would have been any real progress on land reform with more and more communities successfully gaining control.”