Shelter was founded in England in 1966 by the Reverend Bruce Kenrick, who was horrified by the state of the tenements round his Notting Hill parish. The setting up of the organisation in Scotland followed in 1968.
Kenrick had formed the Notting Hill Housing Trust three years earlier to provide decent, affordable houses to rent in the area.
Born of squalor
As slums proliferated in the inner cities, homeless families were forced into overcrowded hostels, and notorious landlords like Peter Rachman made the headlines, Kenrick saw the need for a national campaigning body to complement the work of charities providing housing. Shelter was born.
Cathy Come Home
1966 was also the year that the BBC screened Ken Loach's film about homelessness, Cathy Come Home.
Watched by 12 million people on its first broadcast, the film alerted the public, the media, and the government to the scale of the housing crisis, and Shelter gained many new supporters.
Watch a clip of Cathy Come Home below, or order the film on You Tube.
Since Shelter's foundation, our country has undergone a long period of affluence and economic growth - but complacency allowed housing to slip down the public and political agendas.
More than four decades of constant lobbying have pressured government into making some key changes to policy and legislation, and Shelter has celebrated some landmark achievements in recent years - for example the introduction of the Tenancy Deposit Scheme in England. There has also been the groundbreaking commitment in Scotland that by 2012, every homeless person will have the right to a home.
Still work to be done
Today there is a seemingly unbridgeable gulf between the housing haves and have-nots. Housing is now the key factor determining a person's health, wellbeing, and prospects in life.
Because of Right to Buy and a lack of new building, 1.8 million households in England languish on council waiting lists, and the numbers stuck in temporary accommodation have soared.
If you can't afford to buy, and can't get a council house, renting privately may be your only option. But this is often unaffordable to people on low incomes.
The slums of the 1960s are gone, but the housing crisis still exists. Shelter has achieved great things in its history, but our work won't stop until everyone in Britain can access a decent, affordable home.