CHILDREN'S LITERATURE has long had a love affair with the Middle Ages. Besides a certain "period" charm, tales set in the world of Beowulf or King Arthur provide opportunities for the swashbuckling adventure children love, the kind of thing once described as "the defense of a narrow place against odds." But in a remarkably concentrated way both medieval people and children (especially adolescents) also tend to be racked by the same fundamental questions: How should a person live? To what values should he give his allegiance? What matters?

Julia Cunningham's latest novel, Wolf Roland, blends fable, saint's life, and quest romance into a moving, if somewhat somber, fantasy on these existential questions. Middle-aged Tegonec and his worn-out donkey Fanfare make their living by carting produce for farmers. One night a ravenous wolf attacks Tegonec's camp, carrying off and devouring poor Fanfare. Tegonec goes mad, pursues the wolf, and demands that the wild animal assume responsibility for his action, claiming that "the destroyer must become that which he had destroyed." Rather to Tegonec's astonishment (and awe), the wolf docilely takes up position between the shafts of the cart.

Soon we learn that this is no ordinary wolf: not only subject to remorse, the beast is capable of speech. The introspective Tegonec quickly begins to nourish a secret hope that he may become recognized as a saint, perhaps someone like St. Jerome, who tamed a lion. Along with the newly christened Roland, this peasant dreamer quickly tumbles into various unwanted adventures, in nearly all of which he reveals an innate kindness and chivalry. Yet the world this odd couple inhabits scarcely resembles shining, knightly Camelot; this is the real Middle Ages, a time of blood and burning, where marauding bravoes set the torch to houses, villages, and even castles. On their travels the man and wolf appropriately encounter various Chaucerian riffraff, including a treacherous tavern-keeper, wine-guzzling boorish barons, superstitious peasants, and the sleek fat Madame Grue who starves children in her poorhouse orphanage. One of the bony urchins, named Triggot, joins the duo and eventually helps Tegonec to the verge of another of his daydreams--to be rich and powerful. The man and boy find themselves in the courtyard of a bored king who has promised a feudal suzerainty to whoever solves a certain riddle. During the day all has been bright and cheery, with streamers floating from the windows.

"By nightfall the scene had changed. No one sang but an old crone who was crazily dribbling water over her head from the well, and the complaints at the delay in getting to see the king rose like mosquitoes in the damp air. Fires had been laid on the paving to keep the contestants warm, and some were cooking what they had brought with them; but the colors had been erased with the coming of night, and even the banners hung limp."

Like this contrast between day and night, so is Tegonec's disillusionment when he realizes the cost of becoming a courtier. He has lost the noble Roland and the worshipful Triggot. Immediately he abandons his silky life to wander forth in search of his hitherto undervalued friends, hoping for expiation.

As in other novels by Cunningham (including the once controversial Dorp Dead), the hero of Wolf Roland is a confused lonely figure--indeed, Tegonec, Triggot, and Roland are all orphans of sorts, forlorn until they find one another. The various stopping places of Tegonec's journey describe their trying out of various homes--a monastery, the ruined manor of a widowed chatelaine, the king's castle--but the trio can become a family only after Tegonec has come full circle to the hut where he began. All this is part of the quest romance tradition; in fact Cunningham rather overemphasizes the stages-on- life's-way quality of the adventures at the expense of their excitement. This leaves her novel slightly stiff and figural, an impression emphasized by Roland's grave and elevated speech and Tegonec's saintly desperation.

To some adults Wolf Roland may then seem rather sobering, a study in shades of brown. But adolescents, newly alert to questions of identity and morality, should enjoy following Tegonec as he learns the proper value of friendship, personal integrity, simplicity, and kindness. CAPTION: Illustration, copyright (c) 1983 by Michael Garland from"Wolf Roland"