Exclusive look behind locked doors at the Sainsbury Centre for Visual Arts

Since I sat cross-legged in front of John Davies' Bucket Man, drawing his life-sized figure in Primary School, the centre has had great significance throughout my life.

I went behind the scenes with Calvin Winner, curator and head of collections at the Centre, to see the rooms shut away from the eyes of the public.

Sir Robert and Lady Lisa Sainsbury, founders and key benefactors of the centre, were passionate about acquiring pieces of art and pioneering in their vision to display the work.

Sir Robert Sainsbury was part of the generation which turned Sainsbury’s from a grocery store, into the corporation we know today. Sainsbury’s was one of the first companies to expand into the American concept of a supermarket. Alongside this, he started the now 5,000-piece-strong collection in 1929, before marrying Lisa in 1937 - the couple continuing to collect together.

Initially Sir Robert collected fine books, through which he went on to look at art. The work of Jacob Epstein was one of Sir Robert's first acquisitions and through Epstein, he was introduced to Henry Moore, then in his late 20s. These artists were inspired by ancient art and cultures across the world, which later inspired the Sainsburys' interest to grow this element of their collection.

The couple set aside a (relatively modest, I'm told) pot of money for acquisitions each year and became “acquirer(s) of things” they had emotional responses to; collecting art which spoke to them, with which they connected, and to put it simply, just loved.

A story of friendship, the Sainsbury's formed strong bonds with the likes of Francis Bacon, Norman Foster and Frank Thistlethwaite, which became a powerhouse of companionship, key to to creating the legacy we are blessed to have on our doorstep today.

Calvin Winner talks of the Portrait of R. J. Sainsbury, 1955, by Francis Bacon: "Lisa asked whether he would paint a picture of Robert and it was the one-and-only time he agreed to do a commission.

"At the time, Bacon was actually living quite a nomadic life in Battersea with some friends who had a room spare. He had one room where he painted and slept.

"Robert Sainsbury would leave his office, on the Southbank of the Thames, and head over on his lunch break to Battersea to sit for this portrait.

"He would take his packed lunch and sit in this cold back bedroom, with his pack of sandwiches, and Bacon would paint his portrait.

"Like a lot of artists, Bacon would not show the sitter his work. He was also notorious for destroying his work, but he didn't destroy this one.

"Bacon would aim to get the whole personality of the person, the complicated nature of us humans."

Francis Bacon went on to paint a series of paintings of Lady Lisa Sainsbury, of which the Centre have three.

Soon, the couple had run out of room in their London townhouse, and sought to move their acquisitions to a bigger home. In 1973, they announced that they would donate their very personal collection (coined "the gift") to the University of East Anglia, after a chance meeting with the first vice chancellor, Frank Thistlethwaite, at a dinner party.

The couple saw the opportunity to work with a new university to create something new themselves, gifting the UEA an art collection, which many great universities were acquiring.

They worked with young Norman Foster to design a building as iconic as the then around 800-piece legacy in which it was being designed to hold, and by 1978, the Centre opened its pioneering doors.

The Sainsburys were crucial in helping Foster launch his career, and the centre was his first major public building, recognising it as one of his most important.

I could name drop on behalf of the centre, home to Edgar Degas, Henry Moore, Francis Bacon, Alberto Giacometti, but this is not the only reason the collection is world-renowned. It's all down to the pioneering moves of Robert and Lisa Sainsbury.

Sir Robert and Lady Lisa wished to provide something different from that which museums of the period currently offered. Museums were formal, often considered stuffy, and made for learning, and objects were categorised into types and dates.

The Sainsbury's "wanted an intimate space where art could become part of your everyday experience", mixing activities and interest groups with social spaces, cafes and teaching all in one place, whilst objects were presented equally, regardless of time or place, to work with the "universal nature of art". This was a radical social experiment, and key in changing the British art gallery experience.

The Sainsbury Centre stands for so much of what we know of experiencing art today. The conservation team keeps the works within the world-renowned, free, permanent collection alive, alongside paid-for temporary exhibitions, whilst the prestigious sculpture park grows within the 350-acre parkland.

As the collection grows and more benefactors donate to the long list of acquisitions, Calvin Winner says: "We want to keep the collection alive, and we do that by adding pieces to it... We would hope that they [Sir Robert and Lady Lisa Sainsbury] feel we have maintained what they started and that their legacy is secure."