Childhood

Maria Teresa was born on 29 June 1725 in Novellara. She was the eldest daughter of Alderano I Cybo-Malaspina (1690-1731), Duke of Massa and Prince of Carrara, and his wife, Countess Ricciarda Gonzaga di Novellara (1698-1768). As the ducal couple had no sons, and with the Salic law derogated in Massa and Carrara by virtue of a 1529 decree from Emperor Charles V,^[2] she was her father's primary heiress. Thus, when he died on 18 August 1731, she succeeded him aged only six, under the regency of her mother.

Marriage and adulthood

Her position as the sovereign of the two, however small, Tuscan states made Maria Teresa an attractive match.

With the aim of establishing a second Savoy state in central Italy, Prince Eugene of Savoy, a cadet of a collateral branch of the family, and a prominent member of the imperial court, requested the hand of the very young duchess for his great-nephew Eugene Jean, Count of Soissons, the only male descendant of his family line, and obtained the approval of Emperor Charles VI and the King Charles Emmanuel III of Sardinia, whom he looked to as the head of the family.^[3] Matrimonial agreements were signed in Vienna, where the prince resided on 2 May 1732, and, in the month of October, the seventeen-year-old betrothed visited Massa to pay homage to his little fiancée and future mother-in-law. The marriage, however, could not take place due to the young count's premature death in Mannheim on 23 November 1734.^[4]

The death of the Savoy pretender did not lead to any waning of the emperor's interest in the marriage of the duchess of Massa, and, after a couple of princes from Germany had also proposed themselves, in the end the choice for the candidacy fell on Ercole Rinaldo d'Este, the last scion of the Modena dynasty, who was even two years younger than Maria Teresa.^[5] For the House of Este, the two small Tuscan states would mean regaining a coveted access to the sea^[6] (after the loss of the Duchy of Ferrara a century and a half earlier).

For some years, however, the regent Ricciarda Gonzaga proved adamant in refusing to consider further candidatures, given the still childish age of her daughter.^[7] And this despite the fact that, for her part, she had not yet completely renounced her aspirations on her family's ancestral County of Novellara and Bagnolo, an imperial fief left vacant by the childless death of her brother Filippo Alfonso Gonzaga (and now temporarily entrusted to her administration), which put her in a position to depend on the emperor's favour.

When the little duchess turned 12 in 1737, the emperor insisted again: Ricciarda's uncle, Marquis Carlo Filiberto II d'Este-San Martino (1678 –1752), was once again instructed to return to Massa and reopen the negotiations, also on behalf of Francesco III d'Este, Duke of Modena, father of the groom. This time the regent consented and matrimonial agreements were signed on 20 March 1738. The bride was given a dowry of one hundred thousand scudi, but the Duke of Modena, for his part, undertook to increase by twenty thousand scudi, with his own funds, each of the dowries established for Maria Teresa's two younger sisters by their late father. After the marriage, the duchess should associate her husband in the government of her states, while the duke of Modena, who in 1737 had received the imperial investiture of the County of Novellara and Bagnolo, undertook to implement, in favour of Ricciarda Gonzaga, the separation of her family's allodial estates from the feudal rights, and, again after the marriage, to leave her the full governance of the fiefdom for life, "so that the transferor would retain but his sovereign rights, of which he may not divest himself."^[8]

The marriage, still, had to be postponed until 1741 so that the young Ercole would at least approach the threshold of 14 years. The wedding was finally celebrated by proxy in Massa on 16 April, with Maria Teresa's great-uncle, Carlo Filiberto d'Este-San Martino representing her husband,^[9] but the bride remained in her homeland until autumn, starting an intense correspondence with the duke, her father-in-law, which showed the favour and good disposition with which she had welcomed the marriage.^[10]

Relations between the two young spouses immediately proved stormy. Ercole Rinaldo, who had been forced into marriage by his father, showed from the beginning a profound and radical intolerance towards his wife (which over time even grew into disgust).^[11] He would make public displays of contempt towards her, threatening to send her back to Massa, and also invited her to have their marriage annulled for once and for all: "Look, I understand that you are not for me and I am not for you, so tell the Duke that I will be content». In the desperate letter reporting these words from her husband that she sent to her great-uncle less than a year after her wedding, the duchess complained about the treatment inflicted upon her, adding:

Wherefore my fancy for it all has gone: in any case I intend to give it a try, obliging him with a world of refinements, and, shouldn't I even succeed in this way, I would then beg you for your assistance so that this marriage may be dissolved. Further, not only does the present afflict me, but even more so does thinking about the future, while I consider, if these first months have been so distressing for me —whereas they will be joyful for all the others— what my future will be like, having to dwell with such bad hearted people. Sorry if I wrote so badly, but I'm writing from bed, because I had to escape notice there if I would not be seen, for I'm so restricted and always have a hundred eyes upon me. I beg you to pay my respects to the Marquise and your little ladies,^[12] to whom I wish a better fate than mine, and I recommend myself once again, reconfirming all my respect for you. Modena 14 Mars 1742. Your most devout and obedient niece. Maria Teresa Cybo.

— Quoted in Alessandro Giulini, Nuovi documenti per le nozze Cybo Estensi, pp. 279-280

The couple's relationships continued to be tense at least until mid-1745, also due to the extra-marital excesses of Ercole Rinaldo, an unrepentant teenage womanizer, who shamelessly lived his affairs in the light of day, and despite Maria Teresa's repeated appeals to her father-in-law and the tellings-off he gave to his son (even if the duke was not exactly a figure to be taken as a model in terms of correct marital relations).^[13] Later, though, from the correspondence of the duchess, who in the meantime had fled to Venice with her husband following the Austro-Piedmontese occupation of the duchy (which lasted until 1748), an unexpected notable change emerges in their life as a couple. "I will tell you" — Maria Teresa wrote to her father-in-law in December 1746, — that I am very happy with the prince, as he has completely changed, and has modified his manners [...] You will have the consolation when you come of seeing us get along together in very good harmony."^[14]

The results of this apparent newfound "harmony" were seen in 1750, when the two finally managed to have their first and only daughter, Maria Beatrice, but it also proved to be short-lived. When Maria Teresa gave birth to their only son in 1753 (who died few months later), it was already generally believed that the deterioration in their mutual relations would not make the birth of further offspring possible. This would most likely bring about the extinction of the main branch of the House of Este, as a consequence of the fact that Salic law excluded Maria Beatrice, as a woman, from the succession.^[15] Thus, in 1753, the fate of Maria Beatrice was decided: with a double treaty with the House of Habsburg-Lorraine, the little princess of less than three years was engaged to Empress Maria Theresa's third son, who was also designated as successor by the duke of Modena in the event of the Este male line's extinction.^[16] In exchange, the Habsburgs undertook never to simply annex the Este duchies to their own domains but to preserve their distinct state identity as a sort of tertiogeniture under the new dynasty of Austria-Este.^[17]

Maria Teresa and Ercole Rinaldo then separated de facto and the occasional complaints forwarded by Maria Teresa increasingly tended to reveal the woman's relief from the awareness that they would not produce results. Finally, in January 1768, Ercole Rinaldo formally asked his father for separation from his wife, which therefore became, as it were, official.^[18] Maria Teresa then tried to distance herself, as much as possible, from the court, regularly visiting her Tuscan states in the summer and withdrawing more and more often to Reggio Emilia, capital of the second of the Este duchies,^[19] where she took up residence in the "ancient Palazzo della Cittadella".^[20] From 1771, her stay in Reggio Emilia became permanent, with only rare formal appearances in Modena,^[19] been only cheered up by the visits of her daughter Maria Beatrice and her son-in-law Ferdinand Karl of Habsburg-Lorraine.^[21]

In June 1744, having reached the age of majority, she had been invested of the Duchy of Massa and Principality of Carrara by Emperor Charles VII^[22] and had received full powers from her mother,^[23] but the latter continued to assist her during her absences until she died in Massa in 1768.

Death

Maria Teresa died on 29 December 1790 in Reggio Emilia, at the age of 65, and was buried in the Basilica della Ghiara.^[24] She was succeeded by her daughter in all her titles.