1. From the "許" character:
* Descendants of King Hyo of the Jin dynasty: This is the most widely accepted origin for the surname. It is believed that King Hyo of the Jin dynasty (a state in ancient China) granted the surname "許" to his son who became the ancestor of the Seo clan in Korea.
* Descendants of the ancient Korean tribe of "許" (Hyeo): Another theory suggests that the surname originated from the ancient Korean tribe of "許" (Hyeo) who lived in the region of present-day North Korea.
2. From the "舒" character:
* Descendants of the "舒" (Su) clan: This theory suggests that the surname Seo comes from a separate clan, originally using the "舒" (Su) character.
3. From other origins:
* Adopting a surname: Some individuals may have adopted the surname Seo, possibly through marriage, social mobility, or other reasons.
Variations in the surname:
* Different Hanja characters: The surname Seo can be written with multiple Hanja characters, including 許 (Heo), 舒 (Su), and other less common characters.
* Regional variations: The prevalence of different Hanja characters for Seo varies across regions in Korea.
Overall, the origin of the Korean surname Seo is complex and multifaceted. While the connection to the "許" character from the Jin dynasty is considered the most likely origin, other theories exist, adding to the rich history and cultural significance of the surname.