1860 –  The first realisation of the candela was made using candles made from whale fat.

1898 – The next step in the history of the candela is the development of reproducible gas lamps. These lamps burned a mixture of pentane gas and air in a wickless burner.

1909 – The first successful attempt at establishing an internationally recognized unit. In that year an agreement was signed jointly by NPL in the UK, the National Bureau of Standards (NBS) in the US and the Laboratoire Central d’Electricité in France adopting a unit, derived from a pentane lamp, but maintained with carbon filament lamps.

1940 – Standards based on blackbodies, heated devices designed to simulate a perfect absorber and emitter of radiation, were first realized experimentally in 1930. By January 1, 1940, the unit of luminous intensity was defined in terms of the brightness of a blackbody radiator at the freezing temperature of platinum. This unit was termed ‘the new candle’ and was widely adopted around the world.

1948 – In 1948 the ‘new candle’ became the candela and was adopted worldwide. It was defined as: ‘;The magnitude of the candela is such that the luminance of a full radiator at the temperature of solidification of platinum is 60 candelas per square centimetre’.