The Qi State established Linzi (present Linzi County of Shandong Province) as
its capital. Qi was already a large and powerful prince before the Spring and
Autumn Period. It neighbored the Chu, Lu and Song States on the south, the Yan
State and the Bohai Sea on the north, the Zhao State and the Qinghe River on the
west and the Yellow Sea on the east.
King Qi Xuanwang built a wall in its south part. The wall ran more than 500
kilometers from west to east, joining the embankment of Yuanhe River and the
north foot of Taishan Mountain. It was referred to as "Great Defense"
in some historical literatures.