Who introduced the four kingdom classification?

Answer: The idea of the classification of the bacterial special was made by the scientist Herbert F. Copeland and he was the scientist who did the initiative of dividing the organisms into four different kingdoms 

The four kingdoms among which the organism was divided by the scientist Herbert F. Copeland are as follows

• Kingdom Animalia
• Kingdom Protista 
• Kingdom Monera
• Kingdom Plantae

And this four kingdom classification was done for the purpose to differentiate single-celled prokaryotic cells from many other eukaryotes.