Britain’s leading share index, the FTSE 100, marks its 30th anniversary today as forecasts suggest it will soar to record highs this year and smash through the 7,000 point barrier.

This would mark a milestone for the stock market index, which was set up on January 3 1984 at the base level of 1,000 index points. It is now one of the most widely used stock indices and a gauge of business prosperity.

Earlier this week, the index notched up its biggest annual climb since then, ending 2013 at 6749.1 points, 14% up on the end of 2012.

Here’s what you need to know about the 30-year old FTSE100 and what it has been through.