János I, full name János Nepomuk Mária József Antal Xavér Vince Alajos Ferenc Szaniszló Bernát Pál Félix, was a Saxon prince from the Albert branch of the Wettin house. From 1854 until his death, he was the fourth king of Saxony. His brother, II. He succeeded King Augustus Frigyes on the throne. Prince János was born in 1801 in Dresden, the capital of the Electoral Principality of Saxony. His father was Crown Prince Miksa of Saxony (1759–1838), III. He is the younger brother of Elector Ágos Frigyes. His mother was the first wife of the Crown Prince, Princess Karolina Mária of Bourbon-Parma (1770–1804), the daughter of Prince Ferdinand I of Parma (1751–1802), dethroned by General Bonaparte, and Mária Amália of the House of Habsburg-Lorraine. the eldest daughter of the Austrian Archduchess (1746–1804), Empress Mária Theresa and the granddaughter of the German-Roman Emperor Francis I (Lorraine). in addition to the king, at the same time their father, the elderly crown prince Miksa, renounced his claim to the throne. Prince János came to second place in the order of the expectants of the throne. He became a member of the committee that drafted the new, moderately conservative constitution of Saxony in 1831. When King Antal died in 1836, Ágos Frigyes took the throne of Saxony. Prince János, the designated heir to the throne, became the king of the country only in 1854, at the age of 53, when his brother II. Ágos Frigyes died as a result of an accident, leaving no successor. In addition to the reorganization of the judiciary in 1855, King János did a lot for the expansion of the railway network, the abolition of the guild system, and also played a large part in the revival of the University of Leipzig. During his reign, the revival of industry and commerce, as well as worked to improve the administration of justice. He also took part in amending the criminal and civil codes and drafting the constitution of his country. On November 21, 1822, in Dresden, János married Princess Amália Augustusta of Bavaria (1801–1877), the daughter of King Miksa I of Bavaria and Princess Karolina Friderika Vilma of Baden, from whom he had He had 9 children. He died on October 29, 1873 (at the age of 71) in Pillnitz. His resting place is in the Holy Trinity Cathedral.

King János I of Saxony (1801-1873) came from the Albert branch of the House of Wettin and ruled Saxony from 1854 until his death. During his reign, he implemented several coinage reforms aimed at unifying the Saxon currency with the other German states and complying with the requirements of the German Confederation and the German Empire. The first reform took place in 1857, when the Saxon thaler was replaced by the Union thaler. , which consisted of 30 silver groschen and contained 16.667 grams of silver. This thaler was a single currency introduced by the German Confederation in 1838 and used by most German states. King János I then introduced the Saxon coat of arms on the back of the thaler and the royal monogram on the front. The second reform took place in 1873, when, after the establishment of the German Empire, the Saxon currency was changed to the gold mark, which consisted of 100 pfennigs and 0.358 grams contained gold. This currency was the unified currency of the German Empire, which was also accepted by the other member states. King János I then changed the obverse side of the thaler, which featured his royal portrait and the inscription "JOHANN KÖNIG VON SACHSEN" (John, King of Saxony).I. The coinage of King János was thus formed as a result of the process of German unification, and he tried to follow German economic and political development by transforming the Saxon currency. After the king's death, he was succeeded on the throne by his son Albert I, who continued his father's coinage policy.