Du Guxin (502-557), Du Guxin is a legendary figure in Chinese history, which is not only reflected in his ability to fight well and make outstanding achievements repeatedly. Most importantly, he gave birth to three daughters who were valued as queens. which are rare in history. People often call him "the father-in-law of the three dynasties" and "the Most cow father-in-law" in Chinese history.
Duguxin Polyhedral Coal Precision Seal, unearthed in 1981 in haanxi Province. Duguxin Seal is a seal made of coal, which is collected in Shaanxi History Museum. It has 8 edges and 26 surfaces, of which 18 are square and 8 are triangular.