According to [link|http://www.ex.ac.uk/cimt/data/olympics/olymindx.htm|this] the mile (1500m actually) was won in 4m 6.0s in Paris in 1900. The 4-minute barrier was considered unbreakable for quite a while. I can't find any records that go back far enough to see when 10min was world-class.

But a 9min mile is still pretty respectable.