Amazon unveils the title for its big-budget ‘Lord of the Rings’ streaming series.

Amazon Prime Video’s long-gestating “Lord of the Rings” series, which will make its debut on the streaming platform in September, officially has a name: “The Lord of the Rings: The Rings of Power.”

In addition to revealing the title on Wednesday, Amazon announced that the series would take place thousands of years before the events of the “Lord of the Rings” trilogy of films adapted from J.R.R. Tolkien’s novels by the director and producer Peter Jackson.

The streaming series, more than four years in the making, represents the most ambitious effort since Amazon began investing in original programming.

The company bought the rights to “The Lord of the Rings” for more than $200 million in November 2017, when there was a power vacuum in the executive wing of its streaming division. Roy Price, then the head of Amazon Studios, was forced to resign a month before the deal, after a producer had accused him of sexual harassment. Jeff Bezos, the Amazon founder, was involved in the negotiations, Variety reported. (Mr. Bezos, who tweets infrequently, promoted the series in a Twitter post on Wednesday.)

The development of the series has been the responsibility of Jennifer Salke, the executive who took charge of Amazon Studios in February 2018. Ms. Salke tapped J.D. Payne and Patrick McKay to be showrunners of the series in July 2018, and production has been underway in New Zealand, where Mr. Jackson filmed his trilogy.

The showrunners said in a statement that “The Lord of the Rings: The Rings of Power” was “a title that we imagine could live on the spine of a book next to J.R.R. Tolkien’s other classics.”