Sermon on the Mound

Twenty years ago this month the then Prime Minister Margaret Thatcher accepted an invitation from the Church of Scotland to speak at its General Assembly.

The speech she gave provoked uproar in Scotland and is believed by many to have been a pivotal moment in the none too happy relationship between the Scots and Thatcher.

But why?

Iain MacWhirter of the Sunday Herald newspaper looks back on what came to be called "The Sermon on the Mound."