Chen Lin of the Song Dynasty was referred to as the "Grand Uncle" due to his familial connections and his significant role in the dynasty. Chen Lin was the granduncle of Emperor Huizong, the 25th emperor of the Song Dynasty. This title was a reflection of his close relationship with the imperial family and his influence on the court.

The Song Dynasty, which lasted from 960 to 1279, was known for its cultural and artistic achievements. Chen Lin, a member of the Chen family, was a prominent figure in the court. His connection to Emperor Huizong, who reigned from 1100 to 1126, was particularly significant. Emperor Huizong was known for his patronage of the arts and his close relationship with Chen Lin, who was his granduncle.

Historical records indicate that Chen Lin held various positions in the government, including serving as the Minister of Rites. His influence extended beyond his official roles, as he was also a skilled calligrapher and painter. His artistic talents and connections to the imperial family made him a respected figure in the Song Dynasty.

One reason for Chen Lin's granduncle status was his marriage to a princess from the imperial family. This union solidified his ties to the royal family and elevated his status within the dynasty. Additionally, his descendants played prominent roles in the government, further reinforcing his granduncle title.

The Song Dynasty's emphasis on family connections and the importance of lineage in political and social hierarchies also contributed to Chen Lin being referred to as the "Grand Uncle." In the context of the Song Dynasty, familial relationships were a crucial factor in determining one's status and influence.

In conclusion, Chen Lin of the Song Dynasty was the granduncle of Emperor Huizong due to his familial connections, his significant role in the government, and the cultural and artistic achievements associated with his name. His influence and status within the dynasty were a testament to the importance of family ties and lineage during the Song period.