With my partner Pierre de Meuron, I had become familiar with Chinese contemporary artists through Uli Sigg [the Swiss collector of modern Chinese art]. It was through him that we had learnt of Ai Weiwei's work, although he was still relatively unknown in the west. One day in 2001 Sigg dropped in to our Basel offices with Ai in tow. We went out and had a very good time together.

After that we all decided to travel to China together. Both Pierre [de Meuron] and I got on with Ai well, he has a wonderful sense of humour and is great company.

Ai is incredibly knowledgeable about the culture of old China – about everything from vases to cities – and this knowledge is reflected in his work, constantly drawing on history and tradition. But at the same time his art is very contemporary and I think this is why we made a good match. In both his work and ours you can glimpse the classical but also the radically contemporary.