All universes are imagined; every memorable poem creates a universe which is sufficient unto itself and abides by its own laws. David Morley's latest collection, The Invisible Kings, devotes all of its 80 pages to the creation of such a universe. It is one made up of the conflicts and mythologies of Morley's own Romany heritage, its various dark gods and underworlds, its norms and constellations and, perhaps above all, its language. The 43 poems published here achieve a unity that is profoundly organic. The collection's title gives forewarning: it is impossible to read the word "invisible" without the kings becoming visible; by trying to imagine their invisibility, they come into view. The strange atmospherics suffuse every page while the balance struck between mystery and disclosure can be breathtaking, never more so than in "Kings", the epic sequence that forms the collection's centre of gravity: "I dream backwards half my life. The same snowdrops by the river. / I watch her pick a penèrka of flowers before I speak with her." Such moments led me to feel that Morley had not so much created a new universe as uncovered one.

Any universe is bound together by language; and Morley brings Romany vocabulary fizzing and crackling into our consciousness: kackaràtchi, kàulochìrilo, choochoonya, retchka, kerpèdy are characteristic of the many sweetly struck notes that occur in a grammar whose graphemes, phonemes and explodents bubble up into a sort of acoustic joy. When I discovered that asanòo mànoosh was a smiling man I felt the presence of something familiar, something I already knew; reading it, the subtlety of the intonation became hearable even though I don't speak the language. The gutturals and cadences, with their faint reminiscences of Native American languages, are never prohibitive. They create the spell within which Morley's universe turns to magic, and led me to ask whether understanding could exist in phonetics alone. The beauty of these sounds, integrated into the poems, is most notable in "Kings": "Address your armagànos to the àngelas, asanòo mànoosh. I am sky-drowned, / her white throat calling - Te Avel Angle Tute Te Avel Angle Tute Te Avel Angle Tute / so like a birdcall [. . .]"

Morley is a generous host. When he inducts us nothing is left confused. Three pages of assiduous annotations complete the collection; and on occasions a note supports an individual poem when the mythology being dealt with requires a little more, as in the case of "Bears": "PawPaw and Paprika, two great bears of the Egyptians / of Lancashire, the Witches' County, Chohawniskey Tem / who, when our camp plucked its tents and pulled out its maps, / walked steadily with the wagons, ambling, always ambling". The ensuing note supplies the geography. I have to say I am usually deterred by poetry that requires further illumination beyond the borders of its own text. But Morley's notes are less freight than signposts to a critical path. They make each poetic statement convincing; they add to the authenticity.

Dante mapped an underworld in terza rima. In order to map his, Morley's principal vehicle is the long line of loose blank verse: lines of 17, 18 even 25 syllables are not uncommon in this book and account for its alacrity of vision: "My kings lie about me. My queens lie about me. They are piled about me. / Shoodrò, they are limb-light. They have been hiding here all day from me. / / Why was I late, who am never late; why am I behind who must herald them. / Their heads are the most fine gold, their locks black as a raven's. / / They are beautiful. They are terrible as with banners. / I see the faces of children. I crawl to a willow. I want to touch the one thing / that is alive".

Balancing lines as long as these, from part III of "Kings", without sacrificing music is an act of hubris. So many syllabic units threaten to confuse the differentia of poetry and prose; almost miraculously, Morley keeps the whole book this side of prose. His long lines suit their subject by following the post-Hughesian trick of evoking physical and metaphysical truths with a matter-of-factness which suggests that everything they talk about is to be expected in this universe.

Les Murray has written of Morley's "refraction of the familiar", and without doubt this book refracts expectation. But more than this, it familiarises the unfamiliar to such an extent that by the end you know you have visited a real place and recognised its essential binding features. One of Morley's central achievements is to bring its strangeness close to our own world, as in "Finn of the Wiles": "The Finn was lolling over some nicked bike, / or a poor rich kid's skinny moped". The everyday drifts in and out of sight and of earshot along the way, but every time it does so the next shift in scale takes you further and further out. In the end, the sounds these poems make are the afterlife of this rare and beautiful book.