Gordon Brown saw the wave of the financial sector riding high and rubbed his hands together.
The tax take was £1 in every £4 coming from that sector.
He prided himself on his 'lightness of touch' which attracted more and more banks here.
To be fair to him, I think most chancellors would have done exactly the same.
But over reliance on any one sector is always fraught with problems. What happens when that sector hits a problem?