|Date of birth||Innsbruck, Tyrol, Austria|
|Date of death||Feb 24, 1685 Mantua, Province of Mantua, Lombardy, Italy|
|Authority||Library of congress id VIAF id|
Not to be confused with Isabella Clara Eugenia, sovereign of the Netherlands.
Isabella Clara of Austria (12 August 1629 – 24 February 1685), was a Duchess consort of Mantua, Montferrat, Nevers (until 1659), Mayenne (until 1654) and Rethel (until 1659) by marriage to Charles II, Duke of Mantua and Montferrat.
During 1665–1671 she was Regent of the Duchies of Mantua and Montferrat on behalf of her minor son. Accused of marrying her lover without Imperial consent, she was forced to take the veil as a nun and imprisoned at the Ursuline monastery of Mantua until her death.
Birth and family
Isabella Clara was born in Innsbruck on 12 August 1629 as the third child and second (but eldest surviving) daughter of Leopold V, Archduke of Further Austria and Count of Tyrol and his wife Claudia de' Medici. On her father's side her grandparents were Charles II, Archduke of Inner Austria and his wife Princess Maria Anna of Bavaria and of her mother's side her grandparents were Ferdinando I de' Medici, Grand Duke of Tuscany and his wife Princess Christina of Lorraine.
From her mother's first marriage, she had an older half-sister, Vittoria della Rovere, Duchess of Rovere and Montefeltro suo jure and later Grand Duchess consort of Tuscany. From her four surviving full-siblings, her sister Maria Leopoldine was briefly Holy Roman Empress, German Queen, Queen consort of Hungary and Bohemia until her death in childbirth in 1649, and her two brothers Ferdinand Charles and Sigismund Francis were the last male members of their branch who ruled Further Austria and the County of Tyrol.
Duchess of Mantua
On 7 August 1649 was signed at Innsbruck the marriage contract between Isabella Clara and Charles II Gonzaga, Duke of Mantua and heir of the Duchy of Montferrat, under which was stipulated that due to the size of the bride's dowry, all the revenues of the district of Gazzuolo must be given to her. The official wedding between them was solemnized three months later, on 7 November in Mantua. Thanks to this alliance with the House of Habsburg, Charles II was able to remove the French from Casale and then agreed with King Louis XIV of France that the Duchy of Montferrat should not be controlled by Spain but would remain with the Gonzaga family.
The union was orchestrated by Charles' mother Maria Gonzaga, Duchess of Montferrat and former Regent of the Duchy of Mantua –who was an adherent to follow a pro-Austrian foreign policy– and her paternal aunt Eleonora Gonzaga, Dowager Holy Roman Empress. In March 1651, together with her husband and mother-in-law, Isabella Clara accompanied her sister-in-law, Eleonora Gonzaga for her wedding with Ferdinand III, Holy Roman Emperor in Wiener Neustadt. They remained in the Imperial court until May, when they returned to Mantua.
In Revere on 31 August 1652, Isabella Clara gave birth to her only child, Ferdinand Charles, the future and last Duke of Mantua and Montferrat of the House of Gonzaga; however, this didn't helped to overcome the differences between the spouses. Charles II was indifferent to his wife –with whom he marry purely for political reasons–, and had a long-standing relationship with the Countess Margherita della Rovere, with whom he openly lived at Casale. Isabella Clara, with the help of Pope Alexander VII, was able to expelled her husband's mistress to Rome; but this didn't stopped the hypersexuality of Charles II, who continue to had several female and even male lovers.
Tired of her husband's behavior and despite the requests of her mother-in-law to be prudent, Isabella Clara also took a lover, Count Charles Bulgarini, a secretary of the Duke and a baptized Jew from the Mantua ghetto. Their relations at first were secret, but soon were known by all. Due to her affair, Isabella Clara suffered the reject and contempt from the Ducal court. In June 1661 an assassination attempt was made against the Count Bulgarini, but the shot killed his father. In 1660, after the death of her mother-in-law, Isabella Clara also took the title of Duchess of Montferrat. When Charles II died suddenly on 14 August 1665, there were rumors that he was poisoned by his wife's orders. In fact, the Duke died either accidentally after drink an aphrodisiac, or in the midst of a lascivious intercourse.
Already during the life of her husband, Isabella Clara, relying on the advice of her lover, controlled the political situation in the Duchy. Becoming a Regent on behalf of her minor son, she appointed Count Bulgarini as her First Minister and took a neutral position between the Spanish and French Kingdoms, and also kept a cautious policy to achieve the independence of the Duchies of Mantua and Montferrat from the Holy Roman Empire.
In November 1666 she received for her son the Ducal investiture from the Holy Roman Empire, which confirmed his ownership over the fiefs of Reggiolo and Luzzara, since 1631 under the control of the Dukes of Guastalla. During her regency Isabella Clara increased the Duchy of Mantua's territory, strengthening his defenses. Under the mediation of Luis de Guzmán Ponce de Leon, governor of Duchy of Milan, she was able to obtain without hostilities several islands in the Po river which were also claimed by the Duchy of Modena and Reggio. In addition, the actions of Count Bulgarini improved the economic situation of the state with several tax, judicial and law enforcement systems, and the quality of life of the local population.
Imprisonment and death
In August 1669 the Dowager Duchess officially ended her regency, transferring all powers to her son, but because of the dissolute behavior of the young Duke, she had to continue to be engaged in the affairs of state. In August 1670 at Goito Isabella Clara entered into a marriage contract with Ferrante III Gonzaga, Duke of Guastalla, under which their children Ferdinand Charles and Anna Isabella had to be married. Under this contract, Ferrante III named both his daughter and son-in-law joint heirs of the Duchy of Guastalla and the Dosolo, Luzzara and Reggiolo regions. In addition, the Dowager Duchess was able to obtain the approval of the Emperor that, after the death of Ferrante III (who had no surviving male heirs), the Duchy of Guastalla would be passed to her son, as his wife's inheritance.
After the official wedding ceremony of her son with the Guastalla heiress in July 1671, Isabella Clara retired from court and moved to Goito Castle, where she lived with Count Bulgarini, with whom she secretly married shortly after. Perhaps this step was the reason of that on 16 December 1671 by order of Leopold I, Holy Roman Emperor, and with the consent of the Pope, Isabella Clara was imprisoned in a Ursuline monastery and Count Bulgarini in a Dominican monastery. At the request of the Imperial Commissioner, Count Gottlieb von Windisch-Graetz, both Isabella Clara and Count Bulgarini took monastic vows. The Dowager Duchess became a Poor Clare nun.
Isabella Clara died on 24 February 1685 in the Ursuline monastery in Mantua. Her funeral was only attended by her son, and she was buried in the Church of Sant'Orsola. The public memorial service for took place only on 14 May in the Basilica palatina di Santa Barbara.