Joseph II (13 March 1741 – 20 February 1790) was Holy Roman Emperor from 18 August 1765 and sole ruler of the Habsburg monarchy from 29 November 1780 until his death. He was the eldest son of Empress Maria Theresa and her husband, Emperor Francis I, and the brother of Marie Antoinette, Leopold II, Maria Carolina of Austria, and Maria Amalia, Duchess of Parma. He was thus the first ruler in the Austrian dominions of the union of the Houses of Habsburg and Lorraine, styled Habsburg-Lorraine.

Joseph was a proponent of enlightened absolutism like his brother Leopold II; however, his commitment to secularizing, liberalizing and modernizing reforms resulted in significant opposition, which resulted in failure to fully implement his programs. Meanwhile, despite making some territorial gains, his reckless foreign policy badly isolated Austria. He has been ranked with Catherine the Great of Russia and Frederick the Great of Prussia as one of the three great Enlightenment monarchs. False but influential letters depict him as a somewhat more radical philosophe than he probably was. His policies are now known as Josephinism. He was a supporter of the arts, particularly of composers such as Wolfgang Amadeus Mozart and Antonio Salieri. He died with no known surviving legitimate offspring and was succeeded by his younger brother Leopold II.

Joseph II was a son of Maria Theresa and Francis I. He was born on Monday, March 13, 1741, at two in the morning, in Vienna's Hofburg, the Habsburg dynasty's principal house and administrative center. The following day, Joseph Benedict Augustus Johann Anton Michael Adam was baptized by the papal nuncio with the help of no fewer than sixteen other prelates. The godfathers, Pope Benedict XIV and Polish King Augustus III, were represented by delegates. He had 15 siblings of whom 6 died before their adolescence.

Joseph II received a comprehensive and carefully structured education befitting his status as Maria Theresa's eldest son and heir. Joseph's early education was supervised by a group of distinguished teachers selected by Maria Theresa, including, most notably, Pater Anton von Weger and Karl Joseph Batthyány serving as Joseph’s Hofmeister who were entrusted with overseeing his education. In addition to these principal figures, several other tutors played important roles in Joseph’s education. Johann Wilhelm Höller Franz and Bernhard Weickhart were responsible for instruction in Latin and classical studies, providing a foundation in historical and philosophical texts. Jean Bréquin, a Frenchman, was tasked with teaching Joseph mathematics. A great deal of his education focused on history, taught by State Secretary Christoph von Bartenstein.

Despite being an inevitable political arrangement, Joseph's marriage, which occurred when he was nineteen, ended up being a pleasant one for the duration. The marriage was linked to the Diplomatic Revolution, also known as the Austro-French Alliance of 1756. The stunning Madame de Pompadour, Louis XV's mistress, and Prince Wenzel Anton von Kaunitz, the Austrian chancellor, collaborated on it. Louis XV proposed that Joseph, the infant heir to the Austrian throne, wed his niece Isabel of Parma in order to solidify this Habsburg-Bourbon alliance. Joseph, who admired Isabel's appearance when he saw her portrait, was also thrilled, as did Maria Theresa. The wedding was lavishly celebrated in June 1760. The service was conducted at the Augustinian church by Borromeo, the papal legate.

The marriage of Joseph and Isabella resulted in the birth of a daughter, Maria Theresa. Isabella was fearful of pregnancy and early death, largely a result of the early loss of her mother. Her own pregnancy proved especially difficult as she suffered from pregnancy depression, though Joseph attended to her and tried to comfort her.

In 1763 Isabella fell ill with smallpox and went into premature labor, resulting in the birth of their second child, Archduchess Maria Christina (b.d November 22, 1763), who died shortly after being born. Isabella died soon afterwards. The loss of his beloved wife and their newborn child was devastating for Joseph, after which he felt keenly reluctant to remarry.

For political reasons, and under constant pressure, in 1765, he relented and married his second cousin, Princess Maria Josepha of Bavaria, the daughter of Charles VII, Holy Roman Emperor, and Archduchess Maria Amalia of Austria. Though Maria Josepha loved her husband, she felt timid and inferior in his company. Lacking common interests or pleasures, the relationship offered little for Joseph, who confessed he felt no love (nor attraction) for her in return. He adapted by distancing himself from his wife to the point of near total avoidance, seeing her only at meals and upon retiring to bed. Maria Josepha, in turn, suffered considerable misery in finding herself locked in a cold, loveless union. Four months after the second anniversary of their wedding, Maria Josepha grew ill and died from smallpox. Joseph neither visited her during her illness nor attended her funeral, though he later expressed regret for not having shown her more kindness, respect, or warmth. One thing the union did provide him was the improved possibility of laying claim to a portion of Bavaria, though this would ultimately lead to the War of the Bavarian Succession. Joseph never remarried.