ART / Not just an immaculate conception: Michael Levey wraps up his occasional series on great paintings

A FASCINATING history of Italian painting - partial admittedly, yet ranging across the centuries from Duccio to Tiepolo - could be written entirely on the theme of the Annunciation. What it would demonstrate is not merely the high quality of the pictures inspired by the subject but their extraordinary variety.

The story of the Annunciation is told only in St Luke's gospel, and for pictorial purposes its elements are few. The angel Gabriel was sent by God to the city of Nazareth, to announce to the Virgin Mary that she would bear a son named Jesus who 'shall be called the Son of God'. To her question of how this should be possible ('seeing I know not a man'), the angel answered that the Holy Ghost would come upon her and the power of the Highest would overshadow her.

In 15th-century Florence the year began on the feast-day of the Annunciation, 25 March, and the subject was established as traditionally popular in the visual arts, to the point of being commonplace. In the church of the Saints of the Annunciation was treasured a miraculous image of the Annunciation supposed to have been started by a monk and completed by an angel. Few painters in Florence failed to be called on to paint the scene. Unassisted by an angel but sometimes with studio help, Fra Filippo was eventually responsible for some nine or 10 treatments of it.

The Annunciation in the National Gallery is totally from his own hand, and so fresh and spontaneous does the picture seem that the subject might never have been painted before. The story is told with keen, confident clarity and a spring-like air. There is a new-minted brightness about the main figures, their profiles delicately yet firmly incised on the great gold coins of their haloes. Magic gleams of gold subtly irradiate the draperies around the Virgin, and the furniture of her house. And the pure pink and blue of the costumes stir associations of almond blossom and southern skies.

Fra Filippo Lippi tends to be passed over in standard art history, tacitly judged not to be 'important'. But this painting makes us think again. Indeed, it provides one more example of the danger of testing and stretching art on the Procrustean frame of history. Enjoyable and easily assimilable as Lippi's Annunciation is, hard labour and skilful calculation went into making it so. Literally is the result a work of art. And artistry at this pitch of accomplishment cannot but rank as important.

At the heart of the picture lies a duality of vision, and perhaps of feeling too. Everything is a little more complex than it first appears. The composition is divided into two distinct portions, rather like a diptych. The exterior, left-hand area is occupied by the celestial visitor, the interior at the right by the mortal woman. As interpreted here, the subject has touches of the secular, for all its sacred theme. It is grave and dignified in mood, but also intimate and even domestic. Nazareth looks not so different from mid-15th-century Florence. Exotic as the angel is, with his marvellous sweep of peacock wing and his plumed epaulette, he could pass, without them, for a young deacon or a page-boy. The Virgin's neatly coiffed head and high-waisted dress hint at the costume of a Florentine lady of the period, and the courtly exchange between her and the messenger might have been occasioned by the announcement of a forthcoming feast.

The story implies the meeting of two worlds - the interaction of Heaven and Earth. From that encounter some great artists have created scenes of high drama and excitement. Fra Filippo and his contemporaries must have gazed admiringly at Ghiberti's Annunciation in a panel of the bronze North Door of the baptistry, where the Virgin shrinks back startled, one arm upraised protectively, as the tall, cloud-borne angel, commanding attention, is abruptly manifested before her. More quietly and with austere piety, Fra Angelico depicted the angel positively entering the Virgin's cloister-style abode. In a fresco by Botticelli the angel is an ardent, quivering spirit, wafted towards the Virgin like a holy zephyr.

St Luke's narrative not merely allowed but required artists to select the moment they would show. He left unspecified where exactly the scene occurred, saying only that the angel 'came in unto' the Virgin. But he charted a sequence of reactions from her: from initial fear and then doubt to final acceptance of her destiny.

It is typical of Lippi that he should choose the last of these. For him Heaven and Earth meet serenely, and each has its spell. His is an artistic temperament that likes to walk, gracefully, between extremes - whether of emotion or style. He may not be dramatic but he is not dull. If he is not fervently spiritual, he is far from mundane.

He sets his Annunciation not in a cloister or bedroom or garden, but in an enchanted blend of bedroom-cum- garden, getting the best of those two miniature worlds. Walls are dissolved and rooms exposed to the open air with a poetic indifference to climatic reality. Stylistically too, he has a foot in two worlds. The house exhibits his awareness of 'modern', Renaissance perspective, with three-dimensional illusionism that does not always quite work (the bulging pot of lilies in the foreground does not sit convincingly on the ledge). In contrast, the garden is more Gothic and tapestry-like. It suits the angel, kneeling there respectfully apart, weightless on the flower-starred grass, a being who might be the genius of that dark, half-wild sylvan grove.

But the garden is not just a charming piece of genre. A 'garden enclosed' is one of the symbols of the Virgin as immaculately conceived, and her well-ordered house has probably its own significance in the picture as representing the spotless tabernacle of her body which will receive the Son of God. Symbol and fact are merged again by Lippi in illustrating the central mystery of the incident, the descent of the Holy Ghost in the traditional form of the Dove, sent from Heaven by God the Father, whose pale hand extrudes in blessing from the patch of cloud at the apex of the composition. Small and fluttering close to the Virgin, the Dove seems at first glance as unobtrusive as a pet bird, insufficiently realised for its role. Yet, visible on the original painting if not in reproduction, are wonderful, buoyant gilt spirals which trace out its descent, while it hovers in a shimmering radiance, as if it were a supernatural firework or had flown down on wings divinely dusted with gold.

The picture's powerful harmony mood is fostered by its cunning overall design, itself prompted perhaps by the unusual curved top, explicable if the picture was to be fitted into some architectural setting, possibly over a doorway. Its curve has guided the curve of the angel's wings and almost compels the artist to show the figures seated or kneeling - at least not standing. They too curve inwards, their heads inclining towards each other with a sense of reciprocation increased by the fact that the silhouettes of the two figures make complementary, interlocking shapes. Although they are separated so clearly, they relate to each other across a nicely gauged interval of space; and the two heads on the same level, gently nodding, set up a calm and as it were perpetual rhythm.

In the theme of the Annunciation, subject and painter were perfectly matched. And Lippi expressed something profound in the interpretation here where the balance is so beautifully held between Heaven and this world. There might indeed be something worldly in a picture which comes from the Medici palace in Florence and which carries a Medici device of three feathers within a ring, decorating the foreground parapet under the pot of lilies. Some application may be intended to celebrate a birth in the Medici family, but there is a much wider application. Christian and sacred though the theme is, it extends fundamentally to all the world in the continuity of life a promised birth implies. Fra Filippo had direct experience himself, for he had children - not an achievement to be claimed by every Carmelite friar. And, as it happens, his son grew up to provide a rare, additional cause for rejoicing - though Fra Filippo did not survive to see it - by proving a painter no less talented than his father.

Sir Michael Levey was director of the National Gallery from 1973 to 1987. Tom Lubbock returns next week.

(Photograph omitted)