Around the time of the First World War, a young woman was accepted at Newnham College, Cambridge. She came from a humble background: her father was a farm labourer; she was one of 12 children, although not all survived into adulthood. The family lived in cramped conditions in a rented cottage in the village of Great Wilbraham, a bus ride away from the city of Cambridge itself.
Like the other young women coming through the doors for the first time - Newnham then, as now, was an all-women's college - she came to learn. Unlike most of those others, however, her subjects were practical rather than academic - what we might call vocational.
So instead of history, classics or philosophy, she studied how to polish brass, clean corridors and change bed linen. Her job title was cleaner. Indeed it would have been remarkable, given the times and her background, if she had been admitted to Cambridge - or any university - on any other basis.
Some 90 years later, another young woman arrived at Newnham. Her home was ordinary rather than humble. She had spent five years at a local comprehensive before going on to a grammar school sixth form.
Her parents were both teachers in the state sector and she lived in a mortgaged house in a London suburb. In keeping with the times, she had one sibling rather than 11. But this woman came in through the front door, graduating three years later with a degree in English literature.
I know about this because both women are related to me. The maid was Gladys, my grandmother's younger sister; the "scholar" is Anna, my daughter. There are four generations and nearly 100 years between their Cambridge connection. That they were both at the same college was a coincidence. We only discovered about Gladys once Anna had been accepted.
Although particular to me, the story illustrates a tale of 20th century social mobility that applies to us all. My grandmother was in domestic service and took on many of the values of her upper-middle class employers. She encouraged my mother to stay on at school until 15, and after that to work in a variety of clerical jobs before getting married and having children.
The next generation - my brothers and sisters and I - left school with O- levels and A-levels, and have ended up in modest middle-class occupations: teaching and social work. Although Anna was the first of her generation to go to Oxbridge, she has now been joined by one of her cousins, with another likely to follow shortly.
Anna graduated back in 2003, but the story has currency now because of the recently reignited debate about Oxbridge admissions. This has been triggered by two events. One was the publication of research by the Sutton Trust that concluded that entry to Oxford and Cambridge is still dominated by a very small number of schools - just 100 account for a third of all admissions. Over 80 per cent of these schools are in the independent sector, which educates less than 10 per cent of the school population.
When the researchers widened their net to include 11 other leading universities, including Durham, Bristol and the London School of Economics, the same group of schools still supplied a sixth of all new undergraduates in the period 2002-2006.
The second event to reignite the debate was a speech by John Denham, Gordon Brown's new minister for universities. Warming to the theme of the Sutton Trust's report, he went further, suggesting that the top universities were guilty of class bias in their admissions, and that this was "wasting the talent" of bright children from poor homes. Academics, he said, must do more to "identify and nurture the young students of the future".
Many of these students will be studying in further education. It is, after all, a huge provider of courses for both teenage and mature learners. But no matter how you define FE - by including the more academic-oriented sixth-form colleges or not - you won't find any of them listed among that "golden" 100.
It's true that some of the more prestigious sixth-form colleges do send a regular cohort on to Oxbridge and other top universities. But if you narrow the picture to include only FE colleges, then the picture is very different. Cambridge takes only around one in 50 of its undergraduates from FE - a proportion replicated in other leading universities.
Why this should be the case is the key question. Is it down to FE colleges failing to identify or sufficiently prepare potential Oxbridge candidates? Certainly the Sutton Trust researchers found that many teachers and lecturers in the state sector did not have high enough expectations for their most able pupils.
On the other hand, are the top universities really taking the issue as seriously as they might? I went earlier this year to an event at Cambridge specifically organised for those studying in FE. Students from a dozen colleges across Britain spent a day listening to lectures and generally checking the place out. The university also has its own FE access officer who, as well as organising events in-house, goes out to colleges to encourage applications from a wider constituency.
But is this enough? In all sorts of ways, you can't help but notice that the system works against FE applicants. Take the issue of the Oxbridge admissions timetable. Applications have to be in by October 15 of the year before you intend to study - a full three months earlier than other universities.
This is fine if you've spent 15 months in a sixth form preparing and honing your application. But if you are a mature student who has just returned to study after a break in your education, are you really likely to be ready for the next step less than a month after starting your new course? Admittedly, Cambridge does allow a little leeway, but effectively Access students still need to have completed their Ucas application - and made all their other university choices - by that October deadline.
Certainly John Denham thinks that more could and should be done. He points to other figures, which show that the proportion of new undergraduates from the lowest social classes actually fell last year at both Oxford and Cambridge, and declined steeply at Birmingham and Imperial College London.
After 10 years of Labour government, it seems that social mobility has hit the buffers. And that the century-long progression from farm labourer to Oxbridge graduate has come juddering to a halt.
Surely we must change that. And surely, too, we are going to have to look at new, more radical measures if we are to prevent today's FE students waiting another four generations for their talents to be recognised.