I have been there often before. Each time I see something I haven’t noticed before. I’m talking about the extraordinary Stanley Spencer murals that consume the Sandham Memorial Chapel at Burghclere, near Newbury, in Berkshire.

There’s no artificial lighting in the chapel, which is no bigger than a large living room. It was built to remember a soldier who fell in the first world war. Spencer took six years to paint the murals, which depict scenes from the Macedonian campaign in which the soldier, Lt Henry Sandham, was killed.

The light yesterday was perfect, broad spring sun lighting the paintings as I have never seen them. Spencer’s intriguingly over-fed soldiers were everywhere: on the front line, in hospital, in graves and amid a clutter of white crosses, somewhere in the afterlife. In one picture he is able to conjure a perspective that enables you both to look down on a panoramic scene and up into the faces of individuals within the scene.

But in amongst the bloodshed, there are remarkable details – men washing hospital lockers in baths, others changing the bedding on wounded soldiers’ beds. There’s an officer reading a map, and only when you spot the rather bored horse’s head peeping out from below do you realise he is mounted. All the soldiers about him are crashed out on the ground, exhausted.

The last time I came here, by sheer chance, Spencer’s daughter Cherine had come on her annual pilgrimage from Wales. I got an amazing first-hand account of her father’s eccentricities. Was Spencer perhaps the greatest English painter of the twentieth century? I think so. Certainly the most prolific. Sandham is England’s Sistine chapel!