Taejo means great ancestor in the Korean language. There are several of these great ancestors who have contributed to this surname.

King Taejo of Goguryeo ruled for ninety-three years (47 BC-165 AD). He consolidated the five existing clans, and expanded both Korea's territory and governmental control.

The son of a prominent merchant family, Taejo of Goryeo (877-943) defeated the last king of Silla to found the Goryeo dynasty. He again unified the kingdom, and encouraged the establishment of Buddhism as the national religion.

Taejo of Joseon was the founder of the Joseon dynasty. The son of a Mongolian official, he rose through the hierarchy of the Goryeo army and was instrumental in the overthrow of the 400 year old Goryeo dynasty. His reign (1392-1398) was short, due to family strife and murders over the succession to his throne, and the discontent among the fired officials from the previous regime. Before he abdicated, he moved the capital from Kaesong to Hanseong, now known as Seoul, and the undercurrent of his subjects' disapproval led to a resurgence of national interest in Korean heritage and culture.

There is also the city of Daejon, also spelled as Taejon, which is located in central South Korea. During the Joseon dynasty it was called Hanbat, meaning "large field", and Daejon means the same in Hanja, the Chinese characters which were incorporated into the Korean writing. It was a small agricultural village back then, but in the early 20th century Daejon became a transportation hub, and grew into the large city is it today.


Sources:
wikipedia-King Taejo
wikipedia-Daejon

~Contributed by Feiyan Zhou
~Family plaque by Night~Owl Nyentsen