In this grey room containing nine differently proportioned oil paintings on canvas – some wide and long and others upright - you may have noticed a hushed, reverential atmosphere. That’s due partly to the subdued lighting – as requested by the artist Mark Rothko - and partly to the fact that the paintings are huge – and, since they’re without glass, sound-absorbent. But mainly it’s because of the quietly throbbing energy that seems to exude from their deep maroons, wines, reds and blacks, and their impact on other visitors. All suggest variations on a theme – a perfectly balanced frame – like a window - or set of parallel blocks – like doors – with blurred edges floating against a single background colour.

Close to it’s evident Rothko has built up his intense, velvety depths by applying layer upon layer of very thin paint. He diluted and mixed his paint with non-traditional materials so that it would dry quickly. That’s how he was able to achieve soft feathering effects – scuffing successive layers of slightly different blacks or maroons on top of each other without them running together. On several of the works there are drips running in the ‘wrong’ direction - indicating that Rothko tended to re-orientate his canvasses as he worked.

Rothko conceived these works as an entity, providing a total immersion environment. He called them murals, intending their size to draw people in. He didn’t mind whether people experienced his work in a spiritual or sacred way saying famously ‘I take no sides.’ But he didn’t want his work interpreted intellectually. ‘I am not an abstract painter. I am not interested in the relationship between form and colour. The only thing I care about is the expression of man’s basic emotions: tragedy, ecstasy, destiny.’

The paintings here are part of a larger series Rothko was commissioned to make in 1958 for the exclusive Four Seasons restaurant in New York’s sleek, modernist skyscraper, the Seagram Building. The deep maroons reflect the point at which the project went badly wrong. Rothko at first launched himself into the Seagram project enthusiastically, hiring a new studio and experimenting with what would eventually be a set of over twenty paintings to fit the various restaurant spaces. But he was prone to depression and became bitter towards his elite and potentially unappreciative future audience. The paintings became darker – the colour of raw sliced liver in fact – and Rothko is quoted as saying he wanted the “rich sons of bitches to feel sick” while they ate in front of his work.

The commission was cancelled. But ten years later, Rothko donated nine of the paintings to the Tate Gallery, providing specific instructions as to how they should be displayed.