At the outset, the family-patriarch Paddy Cleary (Richard Kiley), his wife, Fiona (Jean Simmons), and children-moved from New Zealand to Australia to help run Drogheda, owned by Paddy's wealthy sister, Mary Carson (Barbara Stanwyck). Over the years, numerous deaths and disasters (fire, a drowning, a goring by a wild boar) were to befall the family.

While the saga recounted the story of the entire Cleary clan, it focused primarily on the lone Cleary daughter, Meggie (Rachel Ward) and her relationship with Father Ralph de Bricassart (Richard Chamberlain). Although they met when she was just a child, Meggie grew up and fell in love with the handsome young Catholic priest who had been banished to the outback for a previous disobedience. Father Ralph was torn between his own love for Meggie, his love for God, and his ambition to rise in the Catholic hierarchy. Spurred on by the spiteful Mary Carson, who was herself attracted to the priest, Father Ralph was forced to choose between his own advancement in the Church and his love for Meggie. He chose the former and soon found himself at the Vatican. As Father Ralph rose quickly through the hierarchy of the Catholic Church (eventually becoming a cardinal), Meggie married a sheep shearer named Luke O'Neill (Bryan Brown), bore a daughter (played as an adult by Mare Winningham), and ended up working as a maid in Queensland. Years later, de Bricassart returned to Australia and to Meggie, who eventually left her husband. In the controversial third episode, the two consummated their relationship in what Newsweek's Harry F. Waters called "the most erotic love scene ever to ignite the home screen," but de Bricassart still was unable to give up the Church. Unbeknownst to him, Meggie gave birth to his son (played as an adult by Philip Anglim), who in an ironic twist of fate himself became a priest before dying in a drowning accident. As in McCullough's novel, the key underlying message of this miniseries was that each generation is doomed to repeat the mistakes and failures of the previous generation.

     While winning the 1983 Golden Globe Award for Best Miniseries, The Thorn Birds was not without controversy. The subject matter of a priest breaking his vow of celibacy was contestable enough, but the fact that ABC chose to broadcast the program beginning on Palm Sunday and running through Holy Week raised the ire of the United States Catholic Conference. In response, McDonald's Corporation initially requested that its franchisees not advertise during the broadcasts. In the end, however, the company simply advised its franchisees to advertise only before Father Ralph and Meggie had consummated their relationship.

     Despite its controversial subject matter (or perhaps because of it), The Thorn Birds garnered an average 41 rating and 59 share over the course of its four-night run, making it then the second-highest-rated miniseries ever, after Roots (1977). Its controversial third episode, in which Meggie and Father Ralph consummated their relationship, was at the time the fourth­ highest-rated network entertainment show of all time (preceded only by the final episode of M*A*S*H, the "Who Shot J.R.?" episode of Dallas, and the eighth episode of Roots). In the end, an estimated 110-140 million viewers saw all or some of the miniseries. TV Guide. in fact, has listed The Thorn Birds as one of the top 20 programs of the 1980s.

     Produced for an estimated $21 million, The Thorn Birds appeared during the heyday of the network television   miniseries,  from   the  late   1970s  to  the  mid­ 1980s, when the form was seen as "the salvation of commercial television." In this context, The Thorn Birds stood out for both its controversial  qualities and its success. Like Roots and The Winds of War before it, family sagas spanning multiple generations, featuring large, big-name casts, and laden with tales of love, sex, tragedy, and transcendence that kept the  audience coming back  night after night. In  1996 ABC broadcast  a sequel to The Thorn Birds. in  which  Father  Ralph and Meggie are again  separated  and  again  struggle with their passion and  their  consciences.  Though widely promoted, the program received far less attention from both critics and audiences.