Who gave the idea to build this wall?

The earliest wall was built during the Spring and Autumn Period (770 - 476 BC). Some historical records reveal that Qi and Chu States built the walls to defend their territories. Duke Huan was the king of Qi State and King Cheng (called Xiong Yun) was the leader of Shu Date during that period. Perhaps, it was them who came up with the idea of building the walls.

Meng Tian