IT'S hard to pin down a precise number of documents held in the Glasgow Archives - the City Archivist, Dr Irene O'Brien, speaks of three or four million related to the city alone - but one thing is sure:

the archives contain a phenomenal part of the city's history.

The oldest document is a Papal Bull from the 12th century. There are more than a million Poor Law applications for parish relief; Glasgow council minutes stretching back to 1574; records for hundreds of city schools; plans of virtually almost every new building built in Glasgow since 1885; and documents relating to the tramways, the police force and various utilities.

There is more, much more - specifically in the realm of private records. These include shipbuilding papers relating to some 20,000 Clyde-built ships; church records; estate records linked to prominent landed families such as the Stirlings of Keir. There are business archives, and documents from the Clyde Navigation Trust, and solicitors' client records back to the 17th century. Here, too, you will find Scottish Labour Party archives and the James Maxton Collection.

It is all, in other words, a historian's and researcher's dream.

The archives, now located at the Mitchell Library, were created 50 years ago, and have an intriguing history.

"The first Charter for the city was in 1175 (Bishop Jocelin won a royal charter authorising the bishops to have a burgh here)," says Dr O'Brien, "and the early documents for the city were kept in the Cathedral and, possibly, the (nearby) Bishop's Palace.

"At that time, the city and the university were run by the Catholic Church, and at the Reformation of 1560 Archbishop Beaton decided to take all the treasures, including the burgh archives, to Paris.

"They remained at the Scots College in Paris but when the French Revolution began, it was decided they might be at risk and should be removed to safety."

As it turns out, some vital papers were lost, the original charter among them. But much survived: a 13th century volume containing city and university charters (which today is part of the Scottish Catholic Archives), the earliest city documents, from 1435, and the city's minutes from 1574.

The remains of the archives were held in several buildings across Glasgow. "Because the archives are the corporate memory of the city," says Dr O'Brien, "they moved to wherever the council was based.

"They were held in the early Tolbooths, then in the third one, part of which you can still see now. There is a reference to someone visiting the city in 1636 and describing how the archives were kept in a room where the walls were lined with iron.

"They moved to the Court House across from Glasgow Green, then to the municipal chambers in Wilson Street-Ingram Street, and, finally, the basement of City Chambers in George Square."

In the 1950s there was much pressure in favour of creating a city archive service (a sentiment that found its voice in the pages of this very newspaper), the argument being the records contained some 400 years of Glasgow history, that Glasgow was, or had been, the Second City of the Empire, and deserved a properly-run archive.

The argument was won in 1964, and the first archivist was Richard F Dell, who had previously been county archivist in East Sussex.

He came north to what was then the fourth-highest-paid job in British archives; he was also "probably the first professionally-qualified archivist in the whole of Scotland," adds Dr O'Brien.

Dell started in August 1964 and did considerable work before the archives were opened to the public the following year.

The operation expanded in 1975 when Strathclyde Region came into being and took on the archives maintenance. Records were added from all the old county council areas.

The service moved to the Mitchell in 1984 ("a colossal job", remembers Dr O'Brien) and remained as tenants until 1996, when it was transferred to Glasgow Libraries. Today it can be accessed at the fifth floor at the Mitchell - a building that is itself a notable part of Glasgow's history.

It was, incidentally, back in the City Chambers where Dr O'Brien, as a schoolgirl, found herself mesmerised by the sight of so many old documents, and decided she wanted to become an archivist.

Today she heads a staff of 11, who field enquiries from all over the globe (family history is a popular part of the service's expertise) and deal with a steady stream of personal callers at the fifth-floor archives reception desk.

Time has been the enemy when it comes to the digitisation of these millions and millions of records. Very little has been digitised "but we are actively looking at what can be digitised and put out there to inform people about Glasgow's history," says Dr O'Brien. Many church and burial records, have, however, been digitised.

If you love history, being an archivist here must be the perfect job. "That's right. I think most archivists would be historians. You need a sense of history, not least because you have to decide what you want to archive. What exactly constitutes an archive? What do you want to keep for the benefit of future historians and researchers?"

As Glasgow Life chairman, councillor Archie Graham, said: "Anyone who wants to know how Glasgow became the great city it is can't miss the opportunity to explore these archives. As well as Glasgow's history, it is also a fascinating glimpse into the lives of the people who have called this city home. It holds unique and comprehensive accounts of Glasgow through the ages."