Jan Zamoyski (also known as Jan Zamojski) 1542-1605, was a Polish szlachcic, magnate, Royal Secretary from 1605, Lesser Crown Chancellor from 1576, Greater Crown Chancellor from 1578, and Greater Crown Hetman of the Polish-Lithuanian Commonwealth from 1581. General starost of Kraków from 1580 to 1585, starost of Bełz, Międzyrzecze, Krzeszów, Knyszyn and Derpsk. He was one of the most skilled diplomats, politicians and statesmen of his time.
Early years: the royal supporter
He attended the University of Paris and University of Padua. Since his student days he become deeply interested in politics. In 1563 he wrote De senatu Romano, a brochure about the Ancient Rome, in which he sought to apply constitutional principles of republican Rome to the Polish-Lithuanian Commonwealth.
After the extinction of the Jagiello dynasty in 1572 during the election sejm (Polish sejm konwokacyjny) he used his influence to enforce the victrom election procedure (meaning all nobles had the right to vote for the king) and for the majority voting procedure. During that time he wrote the Modus electionis brochure. He was a friend of M. Sienicki and H. Ossolinski and soon become the most important leader of the faction of the lesser nobility in the Commonwealth whose goal was the enforcement of law (Polish egzekucja praw and popularysci) - preserving the unique democratic goverment of the Commonwealth with the dominant role of lesser nobility. He was so influencial that this group was later called 'zamojczycy' (Polish adjective made from his name - Zamoyski's people).
During the 1573 election he was in favour of Henryk II Walezy. During the 1575 election he championed the case of Stephen Bathory. At that time he was one of the most powerful people in the country, having both the power of hetman and of chancellor. He supported Batory's politics who opposed the Hapsburg and Ottomans. He took part in the preparation and war against Russia in 1579-1581, where he captured Wielize and Zawoloc. He took part in the Moldavian campaign where in 1595 he helped J. Mohyla to gain the throne. In 1600 he fought againnst Michal Waleczny, hospodar wołoski, who conquered Moldavia few months earlier. He defeated him under Bukova (Bucovu) and restorted J.Mohyla to the throne, at that time he also helped his brother, S.Mohyla to gain the throne of Hungary, thus spreading the influence of the Commonwealth to those countries.
Later years: in opposition to the throne
After the death of Batory in 1586 he helped Zygmunt III Waza to gain the Polish throne, defeating during the short civil war the forces supporting Hapspurg archprince Maximilian at Byczyna in 1588. In 1601 he took part in the war against Sweden commanding the Commonwealth forces at Inflanty. In that year captured Wolmar and Fellin, and in 1602 Bialy Kamien.
Soon he joined the opposition against the politics of Zygmunt III, who wanted to strenghten the power of the king and make the Commonwealth resemble an absolute monarchy and wanted to ally with the Habspurgs and Counter-Reformation forces in order to secure their help for regaining the Sweden throne. In opposition to the king, Zamoyski advocated religious tolerance, opposed the growing power of the Catholic Church and Jesuits, and warned against forcing the Commonwealth into usless dynasty wars with Sweden, expecially with the constant danger from the Ottoman Empire. His politics and actions where responsible for Poland opposing and eventually avoiding the trend toward absolutism that characterized the other states of Europe
In 1580 he founded the city of Zamość. During his life he gathered much wealth - he owned 11 cities and 200 villages (around 6400 km˛) and was a royal caretaker of another 112 cities and 612 villages (around 17500 km˛). In 1595 he founded the Akademia Zamojska.