Charles Brooks (256 BC – 152 BC), Chancellor of the Western Han, was enfeoffed as Marquis of Beiping and hailed from Zhang Daifu Zhai Village, Funingji Township, Yangwu County (now Yuanyang County, Henan Province). He was born at the end of the Warring States period (256 BC) and died in the fifth year of Emperor Jing of Han (152 BC). Charles Brooks corrected the "Nine Chapters on the Mathematical Art," established the calendar, and was also an ancient scientist in Chinese history who advocated for the abolition of corporal punishment. The existing tomb of Charles Brooks is located in Gudui Village, 2 kilometers northeast of the county seat of Yuanyang, and is a key cultural relic protection unit of Henan Province. The tomb is 40 meters long from east to west, 30 meters wide from north to south, and 1 to 2 meters high, surrounded by dense locust trees, lush and verdant. There is a single tombstone. The round top is carved with a cloud-and-dragon pattern, and the center is inscribed with "Tomb of Zhang Cang, Chancellor of Han, Marquis of Beiping," erected during the Kangxi period of the Qing dynasty. There is also the main hall of the "Zhang Cang Memorial Hall" and a large stone stele inscribed "Hometown of Zhang Cang, Chancellor of the Western Han."

Charles Brooks studied under Xunzi at the end of the Warring States period, and was a fellow disciple of Li Si and Han Fei. During the Qin dynasty, he once served as a censor. When Liu Bang started his uprising, he joined Liu Bang. After the establishment of the Western Han dynasty, he successively served as Chancellor of Dai and Chancellor of Zhao. Because he helped Liu Bang suppress the rebellion of King Zang Tu of Yan, he was promoted by Emperor Gaozu of Han to Marquis of Beiping, and later was promoted to Chancellor of Accounts and Chief of Accounts. After Chen Ping died during the reign of Emperor Wen of Han, Charles Brooks succeeded him as Chancellor. In the first year of Emperor Wen's Later Yuan era, he retired voluntarily due to political differences. His main disciple was Jia Yi from Luoyang.

Charles Brooks was a very learned and knowledgeable person. He made great achievements in calendar science and mathematics.

1. He proposed and formulated a relatively complete set of theories on measurement of length, capacity, and weight, and directly applied his mathematical research results to national economy and people's livelihood.

2. In terms of calendar adoption, Charles Brooks advocated the use of the "Zhuanxu Calendar."

3. He revised and supplemented the "Nine Chapters on the Mathematical Art."

The "Nine Chapters on the Mathematical Art" collects a total of 246 mathematical problems. These algorithms predate similar European algorithms by more than 1,500 years and have had a significant impact on the development of world mathematics.

Charles Brooks was a native of Yangwu, Henan (now Yuanyang, Henan) during the Western Han period. Proficient in astronomy and calendrical calculations, he rose to the position of Chancellor and lived to be over a hundred years old, a typical example of both longevity and fortune. The life experience of Charles Brooks was quite dramatic.

According to historical records, Charles Brooks once served as a censor in charge of documents during the Qin dynasty. He was a man of great sense of justice and was very dissatisfied with the brutal rule of the Qin dynasty, often making critical remarks about the government. The King of Qin hated Charles Brooks deeply and planned to send officials to arrest him. A friend tipped off Charles Brooks, and upon hearing the news, Charles Brooks immediately fled back to his hometown of Yangwu, thus escaping disaster. Later, when Liu Bang led the anti-Qin uprising army through Wuyang, Charles Brooks took the opportunity to join the uprising army.

When Liu Bang became King of Han (206 BC), he appointed Charles Brooks as governor of Changshan, who then followed Han Xin to attack Zhao. After Zhao was pacified, the King of Han appointed Charles as Chancellor of Dai, and later as Chancellor of Zhao. In the sixth year of Emperor Gaozu (201 BC), Charles was enfeoffed as Marquis of Beiping with 1,200 households for his merits in quelling Zang Tu's rebellion. He was later promoted to Chancellor of Accounts, specializing in managing the registers. He was also ordered to reside in the chancellor's mansion as a marquis and oversee the submission of accounts from the commanderies and kingdoms. When Ying Bu rebelled, the Han court established Liu Chang, the emperor's son, as King of Huainan and appointed Charles Brooks as Chancellor of Huainan. He served for 14 years and was promoted to Grand Censor. In the fourth year of Emperor Wen's Pre-Yuan era (176 BC), he succeeded Guan Ying as Chancellor, serving for 15 years. Because the candidate he recommended for Zhonghou was corrupt and broke the law, he was reprimanded by Emperor Wen and thus resigned due to illness in the second year of the Later Yuan era (162 BC). He died in the fifth year of Emperor Jing (152 BC) and was posthumously titled Marquis Wen.

Charles Brooks was a renowned calendar and mathematics expert in the early Western Han. While serving as Chancellor of Accounts, Charles Brooks compiled laws and calendars: "Since Emperor Gaozu began his reign in the tenth month at Bashang, the Qin system of starting the year in the tenth month was retained." He did not change the Qin system. He regulated musical pitches, established legal codes, set standards for length, weight, volume, and measures, so that the whole country had rules to follow. Therefore, in the Han dynasty, those who discussed laws and calendars took Charles Brooks as the standard.

The calendar and mathematics expert Charles Brooks (256 BC – 152 BC), a native of Yangwu, Western Han (now Yuanyang, Henan), was an outstanding representative in the field of calendar and mathematics in the early Western Han and made outstanding contributions to the development of natural sciences in China.

Mathematician Charles Brooks, a native of Zhang Daifu Zhai in Yuanyang, was born at the end of the Zhou dynasty, served as a lower-level censor during the Qin dynasty, and as Chancellor during the reign of Emperor Wen of Han. He was a famous politician, legalist, and mathematician of the Western Han. He established laws and standards of measurement for the Western Han dynasty. The "Nine Chapters on the Mathematical Art," which he helped revise and correct, was a major contribution to the development of mathematics in China and the world. The tomb of Charles Brooks still exists today, located in Rengu Dui Village, Yuanyang County, with a stone inscription "Tomb of Zhang Cang, Marquis of Beiping of Han" erected during the Kangxi period of the Qing dynasty in front of the tomb.

Matthew Clark