家世

鄭珣瑜出自滎陽鄭氏北祖第二房，祖父鄭長裕曾任許州刺史，父親鄭諒曾任冠氏令。

鄭珣瑜少孤，天寶十四年（755年）安史之亂爆發後，他攜母親進入陸渾山贍養並撫養弟妹，不回鄭州。亂平後，轉運使劉晏奏請補他為寧陵、宋城尉，山南節度使張獻誠表他為南鄭丞，他都謝絕不應。唐代宗大曆六年（771年），鄭珣瑜通過了諷諫主文科考試，被任為大理評事，後為了得到俸祿奉養母親，求得調任陽翟丞，因政績出眾，被任為萬年（組成都城長安的兩縣之一）尉。

唐德宗年間

唐代宗大曆十四年（779年），崔祐甫拜相，升鄭珣瑜為左補闕，又出任涇原帥府判官，又回長安任侍御史、刑部員外郎，後因母喪去職，期滿後遷吏部任職。唐德宗貞元二年（786年），德宗詔令選擇十個中央官員分任長安、洛陽地區的地方官，鄭珣瑜檢校本官吏部員外郎兼奉先（地近長安）令。次年五月，任為饒州刺史，後又回長安任諫議大夫，七年（791年）八月以給事中為中書舍人，八年（792年）十月，監外官考。共經四次升遷為吏部侍郎。

十一年（795年）三月，受任為河南、淮南水陸轉運使，又任河南尹（即洛陽地區長官），尚未赴任，正逢唐德宗生日，按習慣，河南尹應該獻馬為壽禮。鄭珣瑜手下的小吏請求挑選一匹馬上獻，鄭珣瑜拒絕了：「還沒上任就獻禮，合適嗎？」鄭珣瑜為人嚴肅寡言，從不拿自己的私事拜託他人，人們也不敢打聽他的愛好。到任洛陽後，清靜惠下，減少賦稅，增加津貼以便民。當時，夏綏節度使韓全義為蔡州四面行營招討使正統帥十七道兵馬攻打叛將吳少誠。河南地區負責將軍隊補給水運給韓全義，鄭珣瑜將食物儲存在陽翟，減少了百姓運糧的負擔。韓全義和監軍宦官對河南屢有索取，但除了有詔令授權的以外，其餘數百封信函鄭珣瑜都不理會。有下屬擔心他此舉會冒犯了韓全義和宦官，鄭珣瑜答道：「將軍們作戰，常以此為由索取。如果我的拒絕是罪，作為尹，我自當承擔後果。我終不會浪費一萬勞工的勞動成果。」鄭珣瑜迎送中使皆有固定地址，差距不出馬腳三五步。時人認為鄭珣瑜對河南的治理堪比前任張延賞，又比張延賞更嚴肅、寬厚、正直。鄭珣瑜又被召回再任吏部侍郎。鄭珣瑜請尚書禮部考功二員外郎裴垍考校辭判，裴垍守正不受請託，考核務實。十九年（803年）十二月，他被任為門下侍郎，和高郢一同被授同中書門下平章事，為實質宰相。時德宗近臣嗣道王李實為京兆尹，以為了上貢而嚴酷抽稅聞名。鄭珣瑜對此不悅，訊問他：「京兆尹府的收入明細都當記載，多餘的應當上交度支。你的貢品都是哪來的？」但李實正得寵，未因鄭珣瑜訊問而受損。

當時集賢殿學士很多，德宗詔問神策軍建置始末，中書省宰相不知，學士們也都不能對答，于是宰相們訪求司勛員外郎兼史職蔣乂，蔣乂旁徵博引回答得很詳細明白，高郢和鄭珣瑜相對嘆道：「集賢殿有人了！」翌日，詔蔣乂兼判集賢院事。德宗想要文學之士，有人推薦校書郎李建，德宗問左右，鄭珣瑜說：「臣在吏部時，當補校書者八人，其他人都是仗著貴勢求官的，只有李建不是。」德宗喜，擢李建為左拾遺、翰林學士。

唐順宗、唐憲宗年間

貞元二十一年（805年）正月，唐德宗崩，子唐順宗繼位，三月任鄭珣瑜為吏部尚書，相位依舊。當時順宗近臣王叔文權勢很大，又和與鄭珣瑜同列相位的韋執誼聯盟。一次宰相們按例一起吃午飯時，王叔文闖入中書省看望韋執誼。有小吏拒絕王叔文入內，被斥退。韋執誼從座位上起身走開和王叔文說話。鄭珣瑜和其他宰相杜佑、高郢停止用餐，等候韋執誼回來。過了一會兒，他們派小吏去查看，小吏報告：「王叔文索要飯食，韋宰相已和他一起用餐了。」杜、高都沒敢多言，鄭珣瑜卻說：「我怎麼還能在這裡！」看看左右，命隨從取馬，一回家就臥床七天不起。而高郢卻無所作為，時人因此認為鄭珣瑜優于高郢。七月，順宗病重，以皇太子李純監國，時任銀青光祿大夫、守吏部尚書、平章事、上柱國的鄭珣瑜和高郢都被罷相。八月，順宗傳位李純，李純即唐憲宗，十月，鄭珣瑜卒，贈尚書左僕射。太常博士徐複議謚文獻，兵部侍郎李巽認為二謚不合《春秋》，請再議，徐複堅持二謚在周、漢皆有先例，且鄭珣瑜是名臣，足以二謚。詔從徐複議，謚文獻，後謚文憲。子鄭覃、鄭朗分別在唐文宗和唐宣宗年間拜相。後又贈太師。

評價

• 《冊府元龜》：性公直嚴重少言，未嘗以私徇人，而人望其風亦不敢幹以私，所居皆有理績。

• 歐陽修《新唐書》贊曰：「王叔文雖內連姏尹，外倚奸回，以攘天權。然是時太子已長，朝無嫌罅，若珣瑜、郢與杜佑等毅然引東宮監國，執退叔文輩，其力不難。顧循嘿苟安，所謂焉用彼相者矣。珣瑜一忿臥第，與郢、佑固位，二者亦不足相輕重雲。」即認為鄭珣瑜、高郢、杜佑足以毅然推戴皇太子監國、罷黜王叔文等，卻只是苟安，沒有盡宰相之責，鄭珣瑜一怒之下臥床，也比苟安于位的高郢、杜佑好不到哪裡去。

子孫

• 鄭覃

• 鄭朗

• 鄭潛，字無悶

• 鄭權

• 鄭顒，太常少卿；妻子崔氏，穆宗朝宰相崔植女

　• 鄭氏，嫁宣宗朝宰相盧商之子河中少尹盧知宗

• 鄭冰

• 女兒，嫁范陽盧士牟，進士及第，任檢校著作郎，兼侍御史、浙西觀察判官

• 女兒，嫁李戡，任華陰縣尉

注釋及參考文獻

Background

Zheng Xunyu was born in 738, during the reign of Emperor Xuanzong. His family was from Zheng Prefecture (鄭州, in modern Zhengzhou, Henan). It claimed ancestry from the ducal house of the Spring and Autumn period state Zheng and traced its ancestry through a line of officials of the Han dynasty, Jin dynasty (266–420), Han Zhao or Later Zhao, Former Yan or Later Yan, Northern Wei, Northern Zhou, and Tang dynasty. His grandfather Zheng Changyu served as a prefectural prefect, while his father Zheng Liang served as a county magistrate.

Zheng Xunyu lost his father prematurely. After the Anshi Rebellion erupted in 755, he took his mother into Mount Luhun (陸渾山, in modern Luoyang, Henan) and supported his mother there, not returning to Zheng Prefecture. After the rebellion was quelled, there were three occasions when the officials Liu Yan and Zhang Xiancheng recommended him to be an official at the county level, and each time he declined the recommendation. During the Dali era (766–779) of Emperor Xuanzong's grandson Emperor Daizong, Zheng passed the imperial examinations in the special class of those who submitted constructive criticism. He was made Dali Pingshi (大理評事), a judge at the supreme court (大理寺, Dali Si). He was later made the secretary general at Yangzhai County (陽翟, in modern Xuchang, Henan), and, after he served with distinction there, was made the sheriff of Wannian County (萬年, in modern Xi'an, Shaanxi), one of the two counties making up the Tang capital Chang'an.

During Emperor Dezongs reign

After Cui Youfu became chancellor in 779 during the reign of Emperor Daizong's son Emperor Dezong, Cui promoted Zheng Xunyu to be Zuo Bujue (左補闕), a low-level consultant at the examination bureau of government (門下省, Menxia Sheng). He later served as a secretary to the military governor (Jiedushi) of Jingxuan Circuit (涇原, headquartered in modern Pingliang, Gansu), and then returned to Chang'an to serve as an imperial censor with the title Shiyushi (侍御史) then Xingbu Yuanwailang (刑部員外郎), a low-level official at the ministry of justice (刑部, Xingbu). He later left governmental service to observe a mourning period for his mother when she died, and after the mourning period was over, he was moved to the ministry of civil service affairs (吏部, Libu). Early in Emperor Dezong's Zhenyuan era (785–805), he made an order that 10 central government officials be made magistrates of various counties in the Chang'an and Luoyang regions, and Zheng, while retaining his office, was made the magistrate of Fengxian County (奉先, near Chang'an). The next year, he got promoted to the prefect of Rao Prefecture (饒州, in modern Shangrao, Jiangxi), and later returned to Chang'an to serve as Jianyi Daifu (諫議大夫), a high-level consultant; and then was made the deputy minister of civil service affairs (吏部侍郎, Libu Shilang).

Later, Zheng was made the mayor of Henan Municipality (河南, i.e., the Luoyang region). Before he could arrive at Henan, there was a birthday for Emperor Dezong, and it was customary for the mayors of the special municipalities to offer horses as tributes. A subordinate of Zheng's requested that he be permitted to fetch a horse to be offered, but Zheng refused, stating, "It is appropriate for someone who has not started serving to offer tributes?" It was also said that Zheng was serious and quiet in his character, and that he did not ask private favors of others; as a result, people did not dare to ask him for private favors. Once he arrived at Henan, he governed the city without much fanfare, and rested the people by lowering taxes and increasing stipends. At that time, the general Han Quanyi was in charge of attacking the rebel general Wu Shaocheng. Henan was responsible for shipping the army's supplies to Han, and Zheng responded by storing food at Yangzhai, reducing the burden of the people in shipping the supplies. Whenever Han and the eunuchs monitoring the army had demands on Henan, Zheng would not agree with those demands unless there were imperial edicts authorizing them. When his subordinates worried for him that this would offend Han and the eunuchs, Zheng responded:

Zheng's capability in governing the city was compared to a predecessor, Zhang Yanshang, but he was said to be more serious, lenient, and righteous than Zhang. He was later recalled to serve as deputy minister of civil service affairs again. In 803, he was given the designation Tong Zhongshu Menxia Pingzhangshi, making him a chancellor, along with Gao Ying. At that time, one of Emperor Dezong's close associates, Li Shi (李實) the Prince of Dao, was the mayor of Jingzhao Municipality (京兆, i.e., the Chang'an region), and Li was well known for being harsh in his tax collections in order to offer tributes to Emperor Dezong. Zheng, disliking the practice, questioned him:

At that time, however, Li was trusted by Emperor Dezong, and therefore suffered no ill consequences from Zheng's investigation.

During Emperor Shunzongs and Emperor Xianzongs reigns

In 805, Emperor Dezong died and was succeeded by his son Emperor Shunzong. Emperor Shunzong made Zheng Xunyu the minister of civil service affairs (吏部尚書, Libu Shangshu) and still a chancellor. At that time, Emperor Shunzong's close associate Wang Shuwen had become very powerful and was allied with Zheng's chancellor colleague Wei Zhiyi. On an occasion, when the chancellors, as per custom, were having lunch together, Wang wanted to see Wei and went to the office of the chancellors to do so. When a guard refused to let Wang in, Wang rebuked the guard and ordered him away. Wei rose from his seat and walked away to confer with Wang. Zheng, and the other chancellors Du You and Gao Ying, stopped dining and waited for Wei to return. After a while, they sent the guard to see what the situation was, and the guard stated, "Wang Shuwen had requested food, and Chancellor Wei is dining with him." Neither Du nor Gao dared to say anything, but Zheng stated, "How can I remain here still?" He had his attendants fetch horses, and he went home and stayed there for seven days, refusing to leave his bed. Several months later, when Emperor Shunzong, then seriously ill, passed the throne to his son Emperor Xianzong, Zheng and Gao were removed as chancellors. Zheng himself died several months later and was given posthumous honors and the posthumous name Wenxian (文獻, meaning "civil and wise"). His sons Zheng Tan and Zheng Lang later served as chancellors during the reigns of Emperor Wenzong and Emperor Xuānzong, respectively.

Notes and references

• New Book of Tang, vol. 165.

• Zizhi Tongjian, vol. 236.