Why was Shah Jahan known widely as the BUILDER EMPEROR ????????

Shah Jahan was known widely as the BUILDER EMPEROR because:

• Shah Jahan were personally interested in literature, art and architecture.
• During his regime, there were several important architectural innovations. 
• It was during Shah Jahan’s reign that the different elements of Mughal architecture were fused together in a grand harmonious synthesis. 
• His reign witnessed a huge amount of construction activity especially in Agra and Delhi.