Founder of the Andong Jang clan; one of the three grand preceptors of Andong who helped Taejo Wang Geon at the 930 Battle of Gochang (Byeongsan); posthumous title Chungheon

| Life | 888(전승) |
| Era | 고려 초·후삼국 |
| Clan | 안동 장씨 |
Jang Jeong-pil (張貞弼) is venerated as the founder of the Andong Jang clan. His original name was Jang Gil (張吉), which is the name used in the Goryeosa. He is said to have had the courtesy name Yeongbo (寧父), the pen name Poeum (圃蔭) and the posthumous title Chungheon (忠獻). Sources quoting the Andong Jang Daedong Sokbo say he was born in 888 (second year of Queen Jinseong of Silla) in Shaoxing Prefecture, Zhejiang, China, son of the grand marshal Jang Won (張源).
Accounts of his origin and arrival differ. One version says he came to Silla with his father at five, returned to Tang China at eighteen to pass the civil examination and serve as Minister of Personnel, and later came back; the Digital Andong Cultural Encyclopedia says that he fled unrest at the end of the ninth century with his father, lived in Gangneung and Andong, and settled in Andong in later life; a Sinailbo article gives 892 as the year of arrival. All of this is close to genealogical tradition and cannot be treated as settled fact.
The best-known episode is the 930 Battle of Gochang (Byeongsan) at present-day Andong. When Gyeon Hwon's Later Baekje army met Taejo Wang Geon's forces, he is said to have led local people together with the Gochang magnates Kim Seon-pyeong and Gwon Haeng to help Wang Geon win a great victory. For this he is said to have been raised to Taesa (grand preceptor) with the rank of Samjungdaegwang and Samhan Byeoksang merit subject, while Goryeosa-based accounts say Kim Seon-pyeong became Daegwang and Gwon Haeng and Jang Jeong-pil became Daesang. Wang Geon is said to have raised Gochang County to Andong Prefecture and granted Andong as his seat of origin, which is how the Andong Jang clan began.
Jang Jeong-pil is venerated with Kim Seon-pyeong (founder of the Andong Kim) and Gwon Haeng (founder of the Andong Gwon) as the three grand preceptors of Andong. The Andong Taesamyo shrine (Bukmun-dong), enshrining all three, is Gyeongsangbuk-do Monument No. 15, and its twelve kinds of Goryeo-era relics (22 pieces) are the Treasure 'Andong Taesamyo Samgongsin relics'. Descendants are said to hold rites each spring and autumn; the three lineages can be followed in the Andong Jang founder lineage chart and the Andong Kim and Andong Gwon pages.
There is a tradition that Jang Jeong-pil was a great-great-grandson of Jang Bo-go, the maritime lord of Unified Silla, but the Sinailbo notes that sources proving a migration of Jang Bo-go's kin are lacking and doubts the claim. Accounts also differ between a Zhejiang birth and a naturalized Silla origin, so this entry does not settle the matter. Note that the Indong Jang and Deoksu Jang are separate clans with different founders.
The Digital Andong Cultural Encyclopedia lists the tomb and ritual lodge of Taesa Jang (Jang Jeong-pil) in Seonggok-ri, Seohu-myeon, Andong. Check the current state of the tomb site with the clan association.
His descendants form the Andong Jang clan. The generations between the founder and Jang Sa-gil in the late Goryeo are not documented, so they are joined by a dotted line in the founder lineage chart.