Question: What duchy was founded in 1530 following the actions of the ruler of the Holy Roman Empire at that time?

<P0-S0> Charles V (Spanish: "Carlos" ; German: "Karl" ; Dutch: "Karel"; Italian: "Carlo" ) (24 February 1500 – 21 September 1558) was ruler of both the Spanish Empire from 1516 and the Holy Roman Empire from 1519, as well as of the lands of the former Duchy of Burgundy from 1506. <P0-S1>  He voluntarily stepped down from these and other positions by a series of abdications between 1554 and 1556. <P0-S2>  Through inheritance, he brought together under his rule extensive territories in western, central, and southern Europe, and the Spanish colonies in the Americas and Asia. <P0-S3>  As a result, his domains spanned nearly four million square kilometers and were the first to be described as "the empire on which the sun never sets". <SEP> <P1-S0> The monarchs of Prussia were members of the House of Hohenzollern who were the hereditary rulers of the former German state of Prussia from its founding in 1525 as the Duchy of Prussia. <P1-S1>  The Duchy had evolved out of the Teutonic Order, a Roman Catholic crusader state and theocracy located along the eastern coast of the Baltic Sea. <P1-S2>  The Teutonic Knights were under the leadership of a Grand Master, the last of whom, Albert, converted to Protestantism and secularized the lands, which then became the Duchy of Prussia. <P1-S3>  The Duchy was initially a vassal of the Kingdom of Poland, as a result of the terms of the Prussian Homage whereby Albert was granted the Duchy as part of the terms of peace following the Prussian War. <P1-S4>  When the main line of Prussian Hohenzollerns died out in 1618, the Duchy passed to a different branch of the family, who also reigned as Electors of Brandenburg in the Holy Roman Empire. <P1-S5>  While still nominally two different territories, Prussia under the suzerainty of Poland and Brandenburg under the suzerainty of the Holy Roman Empire, the two states are known together historiographically as Brandenburg-Prussia. <P1-S6>  Following the Second Northern War, a series of treaties freed the Duchy of Prussia from any vassalage to any other state, making it a fully sovereign Duchy in its own right. <P1-S7>  This complex situation (where the Hohenzollern ruler of the independent Duchy of Prussia was also a subject of the Holy Roman Emperor as Elector of Brandenburg) laid the eventual groundwork for the establishment of the Kingdom of Prussia in 1701. <P1-S8>  For diplomatic reasons, the rulers of the state were known as the King in Prussia from 1701 to 1772; largely because they still owed fealty to the Emperor as Electors of Brandenburg, the "King in Prussia" title (as opposed to "King of Prussia") avoided offending the Emperor. <P1-S9>  As the Prussian state grew through several wars and diplomatic moves throughout the 18th century, it became apparent that Prussia had become a Great Power that did not need to submit meekly to the Holy Roman Empire. <P1-S10>  By 1772, the pretense was dropped, and the style "King of Prussia" was adopted. <P1-S11>  Thus it remained until 1871, when in the aftermath of the Franco-Prussian War, the King of Prussia Wilhelm I was crowned German Emperor. <P1-S12>  From that point forward, though the Kingdom of Prussia retained its status as a constituent state of the German Empire, all remaining Kings of Prussia also served as German Emperor, and that title took precedence. <SEP> <P2-S0> The Duchy of Florence (Italian: "Ducato di Firenze" ) was an Italian principality that was centred on the city of Florence, in Tuscany, Italy. <P2-S1>  The duchy was founded after Emperor Charles V restored Medici rule to Florence in 1530. <P2-S2>  Pope Clement VII, himself a Medici, appointed his relative Alessandro de' Medici as Duke of the Florentine Republic, thereby transforming the Republic of Florence into a hereditary monarchy. <SEP> <P3-S0> The uniformity policy was the concept of implementing Swedish law to the dominions of Sweden during the latter's time as an empire. <P3-S1>  It is symbolized by the slogan unus rex, una lex et grex unus ("one king, one law, one people") possibly coined by Johan Skytte, governor-general in Swedish Estonia, Ingria and Livonia. <P3-S2>  However, the phrase is also found in the debates on the possible union of Scotland and England in 1607, when Sir Edwyn Sandys noted King James VI & I's view that for a perfect union there should be unus rex, unus grex, una lex. <P3-S3>  Most notably, the uniformity policy aimed at abolishing serfdom then common in Estonia, Livonia and the Swedish dominons in the Holy Roman Empire (Ingermanland naturally had a free peasantry). <P3-S4>  While implemented in Livonia against the will of the local Baltic German nobles, the Estonian and Pomeranian peasants remained serfs: Estonia had voluntarily submitted to Sweden and thus had been given leeway in keeping the traditional local law code, while Swedish Pomerania had retained its traditional law code when, on behalf of the then ruling Swedish high nobility, the Peace of Westphalia granted it to Sweden while remaining part of the Holy Roman Empire, and not in a formal cession which would have resulted in the implementation of Swedish law. <P3-S5>  Swedish law was thus only introduced to Swedish Pomerania after the dissolution of the Holy Roman Empire in 1806.