The son of J.R.R. Tolkien did far more than just compile and edit his father’s unfinished stories. He helped create the world of Middle Earth.

Last week, amid churning news cycles about impeachment and Iran and global trade deals, an era quietly ended. Christopher Tolkien, the third and youngest son of “Lord of the Rings” author J.R.R. Tolkien, died at the age of 95.

The younger Tolkien, who spent the last four decades of his life completing his father’s grand artistic vision, was one of the great unsung literary heroes of the last century. For countless readers whose imaginations were molded in part by the legendarium of Middle Earth, his passing severs the last living link to another existential plane.

His obituaries variously describe Tolkien as the editor of his father’s posthumous works, or the guardian of his legacy. But that is not quite right—or not quite enough. Christopher Tolkien was more than an editor or a guardian; he was a kind of co-creator with his father of Middle Earth itself.

It was Christopher Tolkien who, in 1975 at age 50, left his fellowship at Oxford University to sort through dozens of boxes of his late father’s unfinished writings, some dating back more than 60 years and most of which dealt with the creation and history of Middle Earth and its peoples—the entire literary universe in which “The Hobbit” and “The Lord of the Rings” take place.

He spent years compiling and editing these fragments and notes, and in 1977, more than two decades after the publication of his father’s acclaimed trilogy, “The Silmarillion” was published. It went on to sell millions of copies in dozens of editions and translations, and served as the foundation for two-dozen subsequent works derived from Tolkien’s archives, culminating with the publication, last August, of “The Fall of Gondolin”—Christopher Tolkien’s final literary contribution to a creative project that now spans more than a century.

From the very beginning, Tolkien had a hand in crafting what would become one of the greatest literary achievements of modern times. As a boy, he would point out inconsistencies in the ornate stories his father told—stories that eventually became “The Hobbit,” first published in 1937 when Christopher was just 13. He helped his father sort through competing versions of stories, histories, timelines, and especially the geography. He drew the now-famous map of Middle Earth that accompanied the 1954 publication of “Lord of the Rings,” giving shape to the world that helped form his imagination, and in turn shaping the imagination of millions.

It is not too much to say that without Christopher Tolkien, we would not really have J.R.R. Tolkien or the fully realized world of Middle Earth. How much poorer we would be without it. Although “The Lord of the Rings” and the entire Tolkien compendium established fantasy as a literary genre, these works were themselves far more than fantasy as we understand the term today. J.R.R. Tolkien called them fairy-stories, but he meant it in a sacramental sense.

The world of Middle Earth, with its elves and dwarves and wizards and orcs, was shot through with meaning, and it revealed something true about our own world, not just about good and evil but about truth, beauty, and goodness as such. That’s why the saga of Middle Earth has resonated down the century. We recognize ourselves in this enchanted world, where the veil between the spiritual and physical is thinner, and in that recognition our world becomes reenchanted, despite the ravages of scientism and secularism and modernity.

Something else about Christopher Tolkien’s life and work must be said. It’s a remarkable thing for a son to realize the unique genius of his father and, instead of trading on that genius to advance his own career and fortune, choose to dedicate his life to the stewardship and advancement of his father’s work. It is hard to imagine the son of a famous man doing that today, which makes the humility and filial devotion of Christopher Tolkien all the more remarkable.

He was a man who in some ways inhabited two worlds, carrying the great truths he apprehended in the peoples and stories of Middle Earth into the way he lived his life and went about his work. We are not likely to see his kind again, at least not in this age.