Bring me my bow of burning gold! Bring me my arrows of desire! Great words from England’s National Anthem, but what are we singing? Inspirational, of course – but how do the members of the Women’s Institute or socialists such as Billy Bragg interpret this powerful poem? As ever the writer William Blake is elusive. It sounds nationalistic but Blake himself was a radical, dismissive of all institutions as repressive. Again, it seems to be Christian but clearly Jesus never visited England and the ‘dark satanic mills’ probably refers to the Church of England. We had an opportunity this week to enter the world of William Blake. Tate Britain, sandwiched between MI5 and MI6, is showing a retrospective for this remarkable painter, printmaker and poet with some 300 of his original works - drawings, paintings, watercolours, woodcuts, and illustrated books. Blake (1757–1827) lived during tumultuous times – the American and French revolutions, which inspired and then disillusioned him, and above all the Industrial Revolution. However, what this exhibition shows is that first of all he was a jobbing etcher, working steadily 9to5 to earn a living. Many of his works are commissioned. It was only in the evening that he let his imagination rip, inspired by his visions. One of his best-known works, the one which appears in my Marks and Spencer’s 100 Masterpieces of Art (1979) is the Ancient of Days. According to Blake, the work was a faithful transcription of a vision he had had while climbing the stairs in his home in Hercules Road, North Lambeth, where he lived throughout the 1790s. In fact, this powerful print from the frontispiece of his 1794 publication Europe: A Prophecy concludes the Tate Exhibition, The curators see this as his defining work. Blake was even working on a version of it while propped up with pillows at the time of his death. At first sight it seems religious, even biblical. The title is derived from one of God's names given by the Old Testament prophet Daniel while there is a direct reference to Proverbs 8:27: " When he prepared the heavens, I was there: when he set a compass upon the face of the depth.” However, this is not the creator God of the Bible but Urizen the Creator, a product of Blake’s own imagined and vivid mythology. It is this fearsome demiurge who is imposes limits on our existence and curtails our own creativity, the very opposite of the God revealed in scripture. Like Jerusalem, it appears Christian but is actually the opposite. This is dangerous stuff and along with his political views Blake’s radicalism should have had him arrested. He wasn’t for the simple reason that no one knew about him and of those who did, most thought he was mad. As part of the Tate retrospective, there is a reconstructed room from the haberdashery shop in Broad Street, owned by Blake’s brother James. Here William invited all and sundry to view his artwork in a one-off, one-man exhibition staged between May and September 1809. But no one came and none of his temperas or watercolours were sold. The only review was hostile. This came as a profound discouragement and disheartened Blake disappears from view for nearly ten years. However, the Tate exhibition does highlight a hugely important but neglected part of Blake’s life. This is shown at the end of the retrospective with a display of 29 prints from 1824, when he was 67, illustrating John Bunyan’s Pilgrim’s Progress. These are now considered a joint production with his wife Catherine who apparently did most of the colouring. Blake had radical views on sexual freedom, a forerunner of the 19th-century "free love" movement. He was critical of the marriage laws of his day and contested the traditional Christian understanding of chastity as a virtue. Much of his work has a sexual undertone. What are the arrows of desire? You would have expected Blake to have lived a life of sexual debauchery – but the very opposite. He had a strong and creative marriage. So the Tate begins its exhibition with two portraits, of William and Catherine, side by side. In fact, theirs was a powerful love story. I’m running out of time but suffice to say their relationship was transformative. Illiterate, Catherine signed her wedding contract with an X but her husband taught her to read and write but more importantly trained her as an engraver. On his death bed Blake is said to have cried, "Stay Kate! Keep just as you are – I will draw your portrait – for you have ever been an angel to me." Strange that someone who railed against institutions and dogma found such support in his marriage. From all accounts he was faithful and collaborative while Kate was hugely supportive of her troubled husband. He may well have had mental health problems: his friend William Wordsworth commented: “There was no doubt that this poor man was mad!” You wonder how much Kate changed her husband’s views over time; she certainly kept him going. Certainly, his later poems place a greater emphasis on forgiveness, redemption and faithfulness. As he himself observed: “The glory of Christianity is to conquer by forgiveness.” So you never know.