The phrase ‘in the limelight’ means at the centre of attention. However, limelight was actually a form of light which was invented in 1825 by burning a cylinder of lime (calcium oxide) that produced brilliant light. This light was used in lighthouses and theatres. In the theatre, the limelight was used to focus a performer to make him/her the centre of attention, and this marks the origin of the phrase ‘in the limelight’.