Volumes of the complete edition of the OED, still in their worn blue dust jackets, spill off a low-slung table in the center of poet Paul Muldoon's office at Princeton University; behind a ring of chairs, the familiar brown spines of the Encyclopædia Britannica crowd two shelves. Encyclopedias of words and worlds are in his blood, as the "boy from Moy"—the young Muldoon, growing up in the Moy, in County Armagh, Northern Ireland—grew up with only The Junior World Encyclopædia in his home.

Over the desk are caricatures of Muldoon, from the Guardian and the New York Review of Books; photographs of the poet's wife, the novelist Jean Hanff Korelitz, and their children, Asher and Dorothy; and a haunting photograph of Muldoon's parents' grave. On leave this semester from his post as director of Princeton's creative writing program but not from his other roles—professor of poetry at Oxford, where he has not yet reached the midpoint of his five-year term; long-time director of the Poetry Society, London; and ongoing visiting professor at Bread Loaf—Muldoon is checking his voice mail.

His round glasses give him the look of a plumper Harry Potter, and he stands, head tilted into the receiver, in his characteristic pose: "my arms crossed, click, under my armpits." Conspicuously gracious on all occasions, Muldoon apologizes once, and then again; he finishes a quarter of an hour later and apologizes once more. Over the dozen or so years I have known him (and, in full disclosure, I am currently an adjunct member of his Princeton faculty), I have seen him in various states of health and temperament, but never has he been less than genial and accommodating.

Muldoon's range is prodigious, as is his output, especially for a poet just under 50. Author of eight volumes of poetry, in addition to children's books, plays and the libretti for three operas by Daron Hagen, he has translated Aristophanes, Ovid and poetry from the Irish, including Nuala ní Dhomhnaill's collection The Astrakhan Cloak (Gallery Press, 1993). He has edited two major anthologies—The Faber Book of Beasts (1997) andThe Faber Book of Contemporary Irish Poetry (1986) as well as, for Ecco Press, The Essential Byron (1989). To Ireland, I (Oxford, 2000), Muldoon's Clarendon Lectures of 1998 on Irish literature preceding his term at Oxford, will be followed by publication of The End of the Poem, by Faber & Faber and Farrar, Straus & Giroux at the end of the term in 2004.

This spring Farrar, Straus & Giroux, his U.S. publisher since 1990, publishes the full texts of his eight collections in Poems 1968—1998 (Forecasts, Feb. 12). In 1968, Muldoon was all of 17 and, a scant five years later, while he was still a student at Queens University Belfast, his first book, New Weather, was published by Faber & Faber (Faber remains today his primary publisher in the U.K.).

New Weather was a strikingly controlled performance for a poet so young. The poems, most in regular stanzaic forms, exhibited what would become recurrent themes and tropes in his work: a tension between an idealized community and a solitary self; local languages (in one, the speaker and his father fish in the river for "spricklies"); a conflation of histories (especially Irish and Amerindian, but also, here, Greek, Italian and English); narratives based on terse, resonant mysteries and told in precise, startling sentences; a playfulness with the devices of poetry; descriptions of occasions both ordinary and extraordinary; and a central interest in transformation.

With his second and third books, Mules (1977) and Why Brownlee Left (1980), as well as with Quoof and Meeting the British (1987), Muldoon extended his gamut of lyrical styles—dry and urbane, lush and incantatory—sometimes in traditional forms and sometimes in verse seemingly shaped willy-nilly. With Quoof, his skillful rhyming and patterning by allusion and etymology led one commentator to remark, "Muldoon can rhyme cat with dog." In Madoc: A Mystery (1990), a book-length narrative strung on a 19th-century utopian plan hatched by the poets Samuel Taylor Coleridge and Robert Southey, the patterns become almost perilously referential, each page's pint-sized poem a mystery for the reader to decode. "The easiest book is the first one, and then after that it just gets so much harder, in terms of reinventing one's self," Muldoon says, mentioning the spookiness of reading a list of the attributes of a "Muldoon poem" in a review by the poet and critic Michael Hofmann. "I just didn't want to know about it." By reinventing, he says, "I don't mean casting around, change for the sake of change, but rather getting back into that sort of core of one's being, and one's emotional, obsessive being. 'Myself I must remake' is Yeats's phrase."

So with the book that followed Madoc, The Annals of Chile (1994), the work becomes more direct and intimate, domestic poems alternating with wide-ranging elegies. Five major poems from the two most recent collections, The Annals of Chile and Hay (1998), employ the same 50 end-rhymes, in the same order, and two of these poems finish the series and then reverse it. A 50-line poem in Hay, "They That Wash on Thursday," ends each line with the word or syllable "hand."

"These patternings are really useful, finally, only for the writer," Muldoon reflects. "The urge to make is what it's about. We're in the engineering business and the architectural business. So you talk about the pattern of a bridge and this echoes that—not even, necessarily, for obvious visual or aesthetic reasons, but because you know that the stress here has to be answered by the stress there. The poem as engineering feat."

Poetry Review's editor, Peter Forbes, has called Muldoon "the most admired and inventive poet of his generation." Muldoon is keenly awarethat excellence is difficult, if not impossible, to sustain. "One of the things about writing poetry that's terrifying about it is that one generally gets worse at it. Wordsworth, for example, was a genius. But he had it downhill all the way; he just got worse and worse. And there are 90 Wordsworths for every Yeats."

Born and raised in rural County Armagh southwest of Belfast by a schoolteacher mother and a laborer father, Muldoon began to write poems in grammar school as a way to avoid a class assignment. Until college, he wrote in Irish as well as English. Long before he left Armagh for university in Belfast, he was encouraged by dedicated mentors; one introduced him to a book called The Faber Book of Modern Verse, "which I read as if it was a comic book, in the sense that I was so totally into it." Another introduced 16-year-old Muldoon to the reigning Irish poet, Seamus Heaney; later, at Queens College, Heaney became his tutor.

In Belfast, with Heaney and two Queens College students a year ahead of Muldoon, Medbh McGuckian and Ciaran Carson, the young poet fell in with the Belfast Group, which also included Michael Longley and Frank Ormsby. "So there was a tradition of close reading by essentially a workshop of practicing writers," he says. Muldoon also relied on the critic Edna Longley, the poet's wife, for readings, as well as on Michael Allen, who for many years remained his first reader. "There was a sense, in other words, of a community of other people, and one was lucky, if one can be lucky, to be part of it."

Concurrently, James Simmons founded a small press and a journal, The Honest Ulsterman; the Belfast Group poets soon started publishing in its pages. "We didn't think of this at the time, but it was 'our' magazine—of course they also published many poets from all over the United Kingdom and Ireland and beyond." In 1971, Ulsterman Publications published Knowing My Place, a "little pamphlet" by Muldoon; some of its poems appeared in his debut Faber collection, New Weather, in 1973. "A small little thing, you know. It probably cost 10 pence, but it was very exciting."

Seamus Heaney became his firm supporter, accepting Muldoon's poems for a Belfast journal he was guest editing, Threshold, and introducing him and his work to Karl Miller, literary editor of the English journal The Listener, and to Charles Monteith, then poetry editor at Faber & Faber.

"Faber & Faber are absolutely brilliant publishers. They're very, very supportive," Muldoon says. "A year or two after my second book, Mules, came out in 1977, it was out of print, and I went to Charles and asked if he would ever think of reprinting it. He was from Northern Ireland, but he had a very plummy accent, and he said, 'No, I don't think so. What we'll do is, we'll publish another book or two by you, and then we'll publish your selected poems, and then after a while, we'll publish your collected poems. That's what we'll do.' They had that kind of unlikely vision, which nowadays sounds lunatic."

For 14 years after he took his degree in English literature, Muldoon worked as a BBC producer in Northern Ireland. Following his father's death in 1985 and a year's fellowship at Cambridge, he moved to the U.S., where after teaching at Columbia, Princeton and the University of Massachusetts at Amherst, he settled at Princeton in 1990. Since his arrival in the U.S., he has received the T.S. Eliot Prize for Poetry, the Irish Times Poetry Prize, a Guggenheim fellowship and the American Academy of Arts and Letters Award in Literature.

From its own founding in 1976, Wake Forest Press was Muldoon's U.S. publisher, beginning with Mules and Early Poems (1985). Jonathan Galassi took on Madoc: A Mystery for FSG in 1991. Muldoon says, "Wake Forest was very understanding. They're a terrific publisher, and their distribution is fantastic, but I'm sure that they'd be the first to agree that it's not quite as fantastic as FSG's."

Among Muldoon's primary influences are Donne, Frost, Yeats and various rock 'n' roll musicians (he is keen on my hearing "Darling Lorraine" from Paul Simon's new CD, You're the One). Each of his worlds trails its own language: idiom, tenor and vocabulary.

"Yesterday I was trying to write a poem for children, and I wanted to use the word manky, which means sort of soiled, nasty. I went to my dictionary of Ulster English, and it wasn't in there, and so I just thought the dictionary was no good. Basically, Ulster English is my language. But, having lived here for so long, I speak a language that includes elements from that and from American English, and indeed, British English." His face softens. "It's a love affair, truly, with the language—no, rather a marriage!"

Yeats's example to Muldoon, besides "re-making," was in his addressing the matter, the material, of Ireland. Muldoon has said he tries to "avoid propaganda"; he is against expressing "a categorical view of the world." The critic Sean O'Brien has noted his "disinclination to make a drama out of a crisis." Yet with characteristic equivocation, Muldoon has also said that a more direct address of politics "might be closer to an aspect of the truth."

"One of the great things that is happening at the moment in Ireland is that the nation is really now in the imagination business, imagining what other positions are and what it's like to be someone else. It's an opportunity for all of us to reinvent ourselves."

But it is Robert Frost who reigns presently in Muldoon's pantheon (Robert Frost's poem, "The Mountain," is the subject of his essay in the January/February 2001 American Poetry Review). "I think Frost is actually—not that we have to make this judgment—the great 20th-century poet. I just love the surface of Frost. It's so alluring, so inveigling, and you always feel that he's putting his arm around you in some way, and leading you into the poem. Then, having brought you in, he usually knocks you around a little bit, rearranges the furniture in the head, as they say."

In his first book, "Wind and Tree," a poem that is a direct response to Frost's "Tree at My Window," enacts this. Stirred by the wind, two trees entwine their branches and grind themselves together, Muldoon writes, but it "is no real fire./ They are breaking each other." The poem may coincidentally describe the action of a Frost poem upon the reader, but its closing lines may most aptly characterize the mercurial enterprise of Muldoon:

Often I think I should be like/ The single tree, going nowhere, // Since my own arm could not and would not/ Break the other. Yet by my broken bones// I tell new weather.