Hornel came to prominence as one of The Glasgow Boys, having been captivated by the distinctive style of James Guthrie and George Henry following his return to Scotland in 1885 from his studies in Antwerp. He struck up an immediate association with Henry, sharing a studio with him and developing a decorative and increasingly symbolic style. This approach was realised most fully in their collaborative 1890 masterpiece, The Druids: Bringing in the Mistletoe. Both artists also made extensive tours of Japan in 1893 and 1894 and the influences they absorbed on these trips were obvious in the works he exhibited to great critial acclaim on his return.

His later work lacked the vitality of his Japanese paintings, becoming increasingly formulaic, as epitomised by his popular scenes of young children playing amongst flowers which he reworked in numerous variations. It is for these later works that he is still chiefly remembered while the early work which placed him at the very forefront of progressive painting in Scotland and did much to earn Scottish art international acclaim, is now largely forgotten.