The Housing Executive was set up as a non-departmental public body in 1971 to take over the housing responsibilities of 65 separate authorities, including the Housing Trust, a small precursor of the Housing Executive.
With hindsight, something like the Housing Executive - a housing authority for the whole of Northern Ireland, divorced from the sectarian politics of both sides - had been on the cards ever since the Caledon affair.
What happened in Caledon in June 1968 is seen by many as the event that sparked the Troubles. Others choose differently, but what cannot be disputed is the fact that housing was a major issue at the heart of Northern Ireland's problems.
The unionist-controlled Dungannon Rural District Council allocated a new house in Caledon to a Miss Emily Seattle, a single 19-year-old Protestant woman.
A certain Mrs Gildernew, the Catholic mother of three young children, occupied and then squatted in a nearby home allocated to - often forgotten - a Catholic man.
In what must be considered one of the most ill-considered, hamfisted operations by a local council, Mrs Gildernew was forcibly evicted a few days later in full view of television cameras.
The images of a front door being broken down and a young mother, bleeding from cuts and clutching an infant daughter, being harried into the street, were broadcast across Britain and around the world. The infant daughter, by the way, was to become a Sinn Fein Stormont minister.
The Cameron Report of 1969 into the causes of disturbances cited unfair allocation of social housing, with many local councils refusing to adopt a points system. The discrimination, it should be said, worked both ways.
The view of Charles, later Sir Charles, Brett is interesting. He was Oxford-educated, briefly a journalist in Paris and then, in 1950, joined the family firm of solicitors in Belfast.
He was a member of the first board of the Housing Executive and became its chairman in 1979. Still later, he became the chairman of a housing association.
Writing in the mid-1980s about how unionists dealt with the housing crisis, Brett, a Labour Party supporter, said: "Protestants and Catholics have traditionally, over several centuries, tended to live in segregated areas in many of the cities, towns and villages of Ulster.
"Second, it is argued that the electoral consequences of new housing can never be ignored and that the siting of new estates to maintain the status quo went no further than in some closely-contested English, Welsh or Scottish constituencies.
"Third, that since Catholic families tend to be larger than Protestant ones, any allocation scheme based on family size must result in discrimination against Protestants.
"There is some truth in each of these arguments. But against them must be weighed the number of well-documented cases brought to public notice by the Campaign for Social Justice; and some of the damningly candid admissions made by indiscreet unionist politicians.
"And if many Catholics in many areas did get houses, there were certainly some Catholics in some areas who had no hope of ever doing so. It is my view that the majority of councils did not consciously, or deliberately, engage in this kind of discrimination; but a minority did so and thereby discredited the whole.
"It is to the discredit also of the Stormont government that it never made any attempt to intervene, or to temper the excesses of some of its followers." All this serves to illustrate the acrid atmosphere surrounding the birth of the Housing Executive. When, in August 1969, the unionist prime minister at Stormont had to ask the British prime minister to put troops onto the streets because law and order had collapsed in important parts of the province's two main cities, Westminster began to take detailed interest.
James Callaghan, the then home secretary, came to Belfast in August 1969 and met the Stormont Cabinet. He recorded the meeting.
"Among the flurry of suggestions I put to them that afternoon, the one that caused the greatest consternation was my proposal that there should be a single authority for the allocation and building of houses. They regarded the idea with near-horror on political and administrative grounds for, of course, it went to the heart of political patronage."
But Callaghan insisted, so the Housing Executive became the sole provider of social housing. The idea was opposed by the Rev Ian Paisley, along with right-wing unionist factions under leaders Harry West and William Craig, but to no avail.
The Housing Executive began under its first chairman, the accountant and businessman Desmond (later Sir Desmond) Lorimer. The new board consisted of five Protestants, three Catholics and an agnostic (Brett).
The Housing Executive was the distinguished offspring of the Housing Trust, which it superseded and whose HQ it occupied.
Homes and estates, usually quite small, set new standards in design and layout. And for the first time since Merville Garden Village, outside Belfast, open spaces were planned and attention paid to landscaping. All this was new and very welcome.
The Housing Executive will be regarded kindly in history. We must hope the future will serve the community as well as it did.