Isabella Clara of Austria was born on 12 August 1629 as the daughter of Leopold V, Archduke of Further Austria and Count of Tyrol and Claudia de’ Medici.
On 7 November 1649, Isabella Clara married Charles II Gonzaga, Duke of Mantua (an area in Northern Italy) in a pro-Austria policy. She gave birth to her only child, Ferdinand Charles, on 31 August 1652. The marriage between Isabella Clara and Charles was unhappy, and he continued to maintain his mistress, Countess Margherita della Rovere.
Isabella Clara soon tired of her husband’s behaviour and took a lover of her own. His name was Count Charles Bulgarini, and their affair was soon public knowledge. An attempt was made on his life, but the shots killed his father instead. Isabella Clara was widowed in 1665, and she was soon suspected of poisoning her husband.
Despite these rumours, Isabella Clara became regent for her minor son, and she appointed the Count as her first minister. In 1669, her regency officially ended but she continued to be involved in the affairs of state. She managed to secure a rich heiress for her son in the form of Anna Isabella Gonzaga. After their wedding, Isabella Clara moved to Goito Castle, where she openly lived with the Count. They probably married in secret not much later. This was probably the reason that Isabella Clara was imprisoned in an Ursuline monastery on 16 December 1671. The Count was transferred to a Dominican monastery. Both were convinced to take monastic vows. Isabella Clara became a Poor Clare Nun.
She died at the Ursuline monastery on 24 February 1685. She was buried in the Church of Sant’Orsola. Her son was the only person to attend the funeral.