What does it mean that Gao Zongnan crossed Lin 'an in the Southern Song Dynasty in four songs?

In the early Song Dynasty, (then Kang Wang) fled to the south of the Yangtze River in order to avoid the invasion and pursuit of the northern ethnic Nuzhen.

In the second year of Jingkang (1 127), Zhao Gou went south from Hebei to Yingtianfu (Shangqiu, Henan), where he ascended the throne as Song Gaozong. Later, Song Gaozong went all the way from Huaihe River and Yangtze River to Hangzhou to restore the Song Dynasty, and promoted Hangzhou to Lin 'an Prefecture. The Southern Song Dynasty (1 127- 1279) was established.

In the first year of Shaoxing (1 13 1), Lin 'an was officially established as the capital, and it was called "Hangzai" (the capital).

In the Jingkang Rebellion, Jurchen captured many royal families in the Song Dynasty, and Zhao Gou, the King of Kang, was one of the people who escaped this trouble. Zhao Gou went all the way from Hebei to Hangzhou to restore the Song Dynasty, and Nuzhen continued to invade south, reaching Hangzhou. Emperor Gaozong had no choice but to escape to the sea and wander around the coast of Wenzhou for four months. Due to the humid weather in the south and the heroic resistance of the soldiers and civilians in the Southern Song Dynasty, Jurchen coach Hong Yan Wu Shu decided to withdraw his troops to the north. When Han Shizhong retreated to Zhenjiang in the north, he was cut off by the Song Dynasty, and as a result, he was forced into Huangtiandang. Song Jun besieged/kloc-0,000,000 herdsmen with 8,000 troops, and the two sides were deadlocked for 48 days. Finally, Jurchen opened the gap with fire and was able to retreat. Jurchen was defeated by Yue Fei in Jiankang again and never dared to cross the river again.