An estimated 10,000 people turned out on Saturday morning to see Renzo Piano and Richard Rogers drive a flock of 30 Herdwick Sheep across Norman Foster's Millennium Bridge in central London.
The Pompidou pair drove the sheep over the bridge as part of the publicity stunt which saw the flock walk from Borough Market to Smithfield Market, as the central event of the London Architecture Biennale.
The duo - who were sporting 'trust me, I'm an architect' T-shirts - appeared unfazed by the presence of Animal Rights protesters who repeatedly bellowed 'shame on you'.
Speaking in the aftermath of the event, Rogers told the AJ: 'It was good fun, I really enjoyed it.'
The sheep were accompanied by 10 butchers in full Worshipful Company of Butchers regalia, sheepdogs, mounted police and several shepherds as they drove their way through the burgeoning crowd.
When the herd reached the North Bank, the sheep were driven to one side, next to the Sheppard Robson-designed Salvation Army headquarters building, where they were rested in the midst of the throng out of the sun.
They then continued through Paternoster Square and Little Britain before arriving at Smithfield for the launch of the St Bartholomew Fair.
Peter Ackroyd, historian, author and president of the Biennale, said the drive celebrated the 'human pathways' of the city.
'It reignites the old human tracks which were used for many centuries by people coming in and out of the city,' he added. See images of the sheep drive here.by Ed Dorrell