BEFORE Harry Potter was even thought of, you could encounter young women in Glasgow encased in scholarly cloaks which would not look out of place in Potter's alma mater Hogwarts.

They were the elected officials at the Queen Margaret Union, the then female-only union at Glasgow University. The purpose of seeking them out on a Friday or Saturday night was not, alas, to take part in some scholarly debate about that day's pressing concerns, but to get signed in so that you could a) continue drinking after the laughably early pub closing time of ten thirty, b)hear music, and c)meet girls.

The success of c) of course depended on whether you had concentrated too much on a). In truth, if drinking was your main priority you would head instead to the Glasgow University Union on University Avenue, then the male students' union where drinking to excess was almost compulsory. The enmity between the two unions was palpable, and even just a few years ago there was a stushie when members of the GUU had to be ejected from the QM for, well, mistaking the dancefloor for the gentlemen's facilities. As the then Herald decorously explained: "The inter-union rivalry has run for years, with the formerly all-male GUU tending to appeal to the more macho elements of the student body and the QMU traditionally catering for more alternative student tastes."

This month the QM is celebrating its 125th birthday after being founded in 1890 by students of the Queen Margaret College in the west end to provide for the female students' social and cultural needs. It is claimed that for a number of years the main activities for the girls was drinking tea and eating strawberries while discussing their education. They bounced around a few premises near the university before finally settling in University Gardens, a tree-lined cul-de-sac where the female students could debate, chat, eat, drink, and generally hang-out. But this division of the sexes was running out of time when the Sex Discrimination Act was passed in 1975. True, the two unions allowed reciprocal use so male and female students could easily mix within the two buildings, although certain bars were off limits. Men who were Glasgow University students then will tell you now that they were all for equality, but some elements of the male union were keener on keeping women out than even the stuffiest of golf clubs.

It was not until 1979 that the QM changed its constitution to allow male students to become members, and the GUU was dragged huffing and puffing into the modern world a year later. As a member of the union explained: "The QM has changed significantly over time. When the building opened, it didn't contain a single bar. As the 'winds of change' continued to sweep through the world in the 1970s, the Queen Margaret Union sought to change the culture of Glasgow's unions. After nearly a decade of persuasion, the membership voted in favour of allowing men to join the Union in 1979. Down the hill, Glasgow University Union took a little more persuading, following suit in 1980."

So students can join either of the two unions - in fact both if they so desire - but the GUU is still male dominated. Meanwhile the QM was making a name for itself with its music policy, attracting cutting-edge bands which later went on to greater things. The story is always told of QM porter Michael McGovern - he still works there - telling Kurt Cobain, the singer with grunge band Nirvana to stop rolling a joint on the QM's front steps. Being a bad-ass rocker, Cobain ignored him and carried on. One curious relic of the night is the band's playlist which still bears the outline of Kurt's boot when he stood on it. It is passed on to every new union president.

When bands were not playing, there were DJs, and Frank Murphy, a DJ there a generation ago once told me: "'When guys my age come up and say they remember me from the QM, I always reply, 'If you met your wife there, I can't be held responsible'.''

It's not easy for student unions these days it has to be said. When student loans were introduced, students were no longer as poverty stricken as they used to be, and the owners of clubs and bars noticed this and began tailoring their offerings to tempt students away from the traditional unions because they now had money to spend. The days of student unions simply offering cavernous drab halls where folk could drink themselves into oblivion for a few quid have gone. They have to up their game to compete.

As the QM spokesman concedes: "Every good story has its dark days, and 1989 proved to be the Queen Margaret Union's. After a decade of financial instability, rumours of closure worried the board of management and the staff. Thankfully the Union weathered the crisis and, thanks to the hard work of the board, staff and membership, ensured the Union could continue to operate. Since then it has continued to prosper at the heart of the university. Its history is unique and diverse, and it has achieved great things."

Nowadays the QM has its large venue, Qudos, coffee shops, a store selling cheap stationery and clothes, Champs Bar on the first floor with pool tables for the sportier students, Jim's Bar where quiz nights take place, a TV room and study rooms. It really is a big business now.

So the anniversary celebrations begin later this month with Professor Green appearing at the union. And no, if you think that Professor Green is an actual academician, then go back to watching Miss Marple on the telly. He is a famous English rapper and singer/songwriter.

But no matter how famous he is, he won't be able to roll a spliff on the front steps if Michael is on duty that night.