In 1569, Cosimo de' Medici had ruled the Duchy of Florence for 32 years. During his reign, Florence purchased the island of Elba from the Republic of Genoa (in 1548), conquered Siena (in 1555) and developed a well-equipped and powerful naval base on Elba. Cosimo also banned the clergy from holding administrative positions and promulgated laws of freedom of religion, which were unknown during his time. Cosimo also was a long-term supporter of Pope Pius V, who in the light of Florence's expansion in August 1569 declared Cosimo Grand Duke of Tuscany, a title unprecedented in Italy.
The international reaction to Cosimo's elevation was bleak. Queen Catherine of France, though herself a Medici, viewed Cosimo with the utmost disdain. Rumours circulated at the Viennese court that had Cosimo as a candidate for King of England. Maximilian II, Holy Roman Emperor and his cousin King Philip II of Spain reacted quite angrily, as Florence was an Imperial fief and declared Pius V's actions invalid. However, Maximilian eventually confirmed the elevation with an Imperial diploma in 1576.
During the Holy League of 1571, Cosimo fought against the Ottoman Empire, siding with the Holy Roman Empire. The Holy League inflicted a crushing defeat against the Ottomans at the Battle of Lepanto. Cosimo's reign was one of the most militaristic Tuscany had ever seen.
Cosimo experienced several personal tragedies during the later years of his reign. His wife, Eleanor of Toledo, died in 1562, along with four of his children due to a plague epidemic in Florence. These deaths were to affect him greatly, which, along with illness, forced Cosimo to unofficially abdicate in 1564. This left his eldest son, Francesco, to rule the duchy. Cosimo I died in 1574 of apoplexy, leaving a stable and extremely prosperous Tuscany behind him, having been the longest ruling Medici yet.
Francesco and Ferdinando I
The Grand Duke Ferdinando I.
Francesco had little interest in governing his realm, instead participating in scientific experiments. The administration of the state was delegated to bureaucrats. He continued his father's Austrian/Imperial alliance, cementing it by marrying Johanna of Austria. Francesco is best remembered for dying on the same day as his second wife, Bianca Cappello, spurring rumours of poisoning. He was succeeded by Ferdinando de' Medici, his younger brother, whom he loathed.
Ferdinando eagerly assumed the government of Tuscany. He commanded the draining of the Tuscan marshlands, built a road network in Southern Tuscany, and cultivated trade in Livorno. To augment the Tuscan silk industry, he oversaw the planting of Mulberry trees along the major roads (silk worms feed on Mulberry leaves). He shifted Tuscany away from Habsburg hegemony by marrying the first non-Habsburg candidate since Alessandro de' Medici, Duke of Florence, Christina of Lorraine, a granddaughter of Catherine de' Medici. The Spanish reaction was to construct a citadel on their portion of the island of Elba. To strengthen the new Tuscan alliance, he married the deceased Francesco's younger daughter, Marie, to Henry IV of France. Henry explicitly stated that he would defend Tuscany from Spanish aggression, but later reneged. Ferdinando was forced to marry his heir, Cosimo, to Archduchess Maria Maddalena of Austria to assuage Spain (where Maria Maddalena's sister was the incumbent Queen consort). Ferdinando sponsored a Tuscan colony in America, with the intention of establishing a Tuscan settlement in the area of what is now French Guiana. Despite all of these incentives to economic growth and prosperity, the population of Florence, at dawn of the 17th century, was a mere 75,000 souls, far smaller than the other capitals of Italy: Rome, Milan, Venice, Palermo and Naples. Francesco and Ferdinando, due to lax distinction between Medici and Tuscan state property, are thought to be wealthier than their ancestor, Cosimo de' Medici, the founder of the dynasty. The Grand Duke alone had the prerogative to exploit the state's mineral and salt resources. The fortunes of the Medici were directly tied to the Tuscan economy.
Ferdinando, despite no longer being a cardinal, exercised much influence at successive Papal conclaves; elections which chose the Pope, the head of the Catholic Church. In 1605, Ferdinando succeeded in getting his candidate, Alessandro de' Medici, elected as Pope Leo XI. Leo XI died less than a month later, but fortunately for the Medici his successor Pope Paul V was also pro-Medici. Ferdinando's pro-Papal foreign policy, however, had drawbacks. Tuscany was overcome with religious orders, all of whom were not obliged to pay taxes. Ferdinando died in 1609, leaving an affluent realm; however, his inaction in international affairs drew Tuscany into the provincial yolk of politics.
Cosimo II and Ferdinando II
Ferdinando's elder son, Cosimo, mounted the throne following his death. Like his uncle, Francesco I, government held no appeal for him, and Tuscany was ruled by his ministers. Cosimo II's twelve-year reign was punctuated by his contented marriage with Maria Maddalena and his patronage of astronomer Galileo Galilei.
When Cosimo died, his oldest son, Ferdinando, was still a minor. This led to a regency of Ferdinand's grandmother, Dowager Grand Duchess Christina, and his mother, Maria Maddalena of Austria. Christina heavily relied on priests as advisors, lifting Cosimo I's ban on clergy holding administrative roles in government, and promoted monasticism. Christina dominated her grandson long after he came of age until her death in 1636. His mother and grandmother arranged a marriage with Vittoria della Rovere, a granddaughter of the Duke of Urbino, in 1634. Together they had two children: Cosimo, in 1642, and Francesco Maria de' Medici, Duke of Rovere and Montefeltro, in 1660.
Ferdinando was obsessed with new technology, and had several hygrometers, barometers, thermometers, and telescopes installed in the Pitti. In 1657, Leopoldo de' Medici, the Grand Duke's youngest brother, established the Accademia del Cimento, which set up to attract scientists from all over Tuscany to Florence for mutual study.
Tuscany participated in the Wars of Castro (the last time Medicean Tuscany proper was involved in a conflict) and inflicted a defeat on the forces of Urban VIII in 1643. The treasury was so empty that when the Castro mercenaries were paid for the state could no longer afford to pay interest on government bonds. The interest rate was lowered by 0.75%. The economy was so decrepit that barter trade became prevalent in rural market places. The exchequer was barely adequate to cover the state's current expenditure, resulting in a complete termination of banking operations for the Medici. Ferdinando II died in 1670, succeeded by his oldest surviving son Cosimo.
The Grand Duke Cosimo III in old age
The Grand Duke Gian Gastone's coronation portrait; he was the last Medicean monarch of Tuscany
Cosimo III's reign was characterised by drastic changes and a sharp decline of the Grand Duchy. Cosimo III was of a puritan character, banning May celebrations, forcing prostitutes to pay for licenses and, beheading sodomites. He also instituted several laws censoring education and introduced anti-Jewish legislation. He imposed crippling taxes while the country's population continued to decline. By 1705, the grand ducal treasury was virtually bankrupt, and the population of Florence had declined by approximately 50%, while the population of the entire grand duchy had decreased by an estimated 40%. The once powerful navy was reduced to a pitiful state.
Cosimo frequently paid the Holy Roman Emperor, his feudal overlord, high dues. He sent munitions to the Emperor during the Battle of Vienna. Tuscany was neutral during the War of the Spanish Succession, partly due to Tuscany's ramshackle military; a 1718 military review revealed that the army numbered less than 3,000 men, many of whom were infirm and elderly. Meanwhile, the state's capital, Florence, had become full of beggars. Europe heard of the perils of Tuscany, and Joseph I, Holy Roman Emperor asserted a remote claim to the grand duchy (through some Medici descent), but died before he could press the matter.
Cosimo married Marguerite Louise d'Orléans, a granddaughter of Henry IV of France and Marie de' Medici. Their union wrought a high level of discontentment, but despite the tension they had three children, Ferdinando, Anna Maria Luisa de' Medici, Electress Palatine and the last Medicean grand duke of Tuscany, Gian Gastone de' Medici. Neither of Cosimo's two sons was a suitable heir; Ferdinando was an alcoholic and epileptic, while his younger son, Gian Gastone, according to historian Paul Strathern, was not appropriate material for the role of sovereign.
Cosimo contemplated restoring the Republic of Florence, a decision that was complicated by the Grand Duchy's feudal status: Florence was an Imperial fief, Siena a Spanish one. The plan was about to be approved by the powers convened at Geertruidenberg when Cosimo abruptly added that if himself and his two sons predeceased his daughter, the Electress Palatine, she should succeed and the republic be re-instituted following her death. The proposal sank, and ultimately died with Cosimo in 1723.
The last years of the Medici
Cosimo III was succeeded by his son, Gian Gastone, who, for most of his life, kept to his bed and acted in an unregal manner, rarely appearing to his subjects, to the extent that, at times, he had been thought dead. Gian Gastone would repeal his father's puritan laws. In 1731, the Powers gathered at Vienna to decide who would succeed Gian Gastone. They drew up the Treaty of Vienna, which gave the grand ducal throne to Don Carlos, Duke of Parma. Gian Gastone was not as steadfast in negotiating Tuscany's future as his father was. He capitulated to foreign demands, and instead of endorsing the claim to the throne of his closest male relative, the prince of Ottajano, he allowed Tuscany to be bestowed upon Francis Stephen of Lorraine. Don Carlos became King of Naples shortly after his arrival in Florence in 1735, by the Treaty of Turin. Soon after, Francis Stephen of Lorraine became heir to the Tuscan throne. Gian Gastone had no say in events and had become quite attached to the Spanish Infante. The Tuscans despised the new occupying "Lorrainers", as they interfered with the Tuscan government, while the occupying Spaniards had not done so. On July 9 1737, Gian Gastone died; the last male Medici of the Grand Ducal line.