I thought that I’d seen enough Picasso.  I thought that I knew all the permutations of his multi-faceted talent.  But despite visiting entire museums dedicated to the modern master, and countless exhibitions, the small collection that the Courtauld has brought together in just two rooms was a revelation.  In my experience pre-Blue Period paintings seem to be largely ignored – perhaps because, as the curator willingly admits, prior to the emergence of these distinctive images Picasso’s debt to the Post-Impressionists was evident.  Yet even those compositions that appear amalgamations of Degas and Toulouse-Lautrec have a verve and style, an assured dexterity that for an artist of only 19 is astonishing.

Here, the shadowy theatrical backdrop, the blurred and ghostly figures behind the bright, artificially lit dancers, and the close cropping of the scene recall Degas’ images of dancers on stage, or the opera Robert le Diable; while the dancers themselves, with their lurid make-up and flash of black stockings are pure Lautrec.  There are shades of Lautrec’s Bohemian underworld too in Picasso’s charismatic portrait of ‘Bibi-la-Puree’, a former actor, one-time secretary to Verlaine and inveterate absinthe-drinker (etre dans la puree apparently meaning to be in dire straits).

The loose expressive brushwork perfectly captures the dishevelled, anarchic vitality of this self-styled King of Bohemia.  Meanwhile, the colours – the turquoise blue of Provencal skies, the mint green of Japanese prints, the pale rose, and the flash of orange and red reveal the hallmark of Van Gogh.

And then suddenly his style changed.  Though the image of the absinthe-drinker is drawn from Degas’ famous painting, the treatment of it is utterly different.  Picasso abandons the painterly brushstrokes in favour of almost flat planes of colour and pattern, a sense of volume and space only grudgingly suggested by simple modulations of colour.  Like Degas’ couple these characters look miserable, caught up in their own thoughts – but Picasso has substituted the bearded Bohemian for Harlequin, who with Columbine has erroneously strayed from his fantasy world into the sordid reality of a Parisian cafe.

Here is the start of the melancholy that pervaded the Blue Period.  These silent, contemplative, desolate figures, with their pale faces and hunched shoulders and with elongated hands enveloping themselves, would be replicated in ever more emaciated guise and steeped in an inky blue light.  It was famously the death of Picasso’s friend Casagemas which started this mournful fixation, and two large paintings are displayed which testify to the profound effect that this had on the artist.  One, an indigo funerary monument, intense as Mantegna’s dead Christ; the other, a surreal imagining of his friend’s funeral with ladies of the night in place of angels, accompanying him to heaven on a white horse in the manner of Chagall’s blue-tinted visions of floating men and beasts.

If anything this trauma spurred Picasso on.  What is difficult to comprehend is that so much work (and only a selection from hundreds of canvases is displayed), and such extensive experimentation, was achieved in just one year: 1901.  The approach of the Courtauld, isolating a short but massively productive period, and one which would prove seminal in establishing the artist’s reputation, is in this sense a masterstroke.  By the end of the year Picasso had made an indelible mark on the Parisian art world.  His self-portrait, shown on the occasion of his first solo exhibition, says it all with the ambitious arrogance of youth – ‘Yo – Picasso’.