Silverstone greeted the field with a shiny new pit complex and a very wet track for opening practice, but it was still Red Bull on top, with Mark Webber leading the way by 0.6 seconds from Michael Schumacher's Mercedes.
Kobayashi crashed heavily in FP1 © LAT
Rubens Barrichello looked strong for Williams in third, as did Sauber's Sergio Perez in fourth, though these were never likely to be the most representative performances of the year given the conditions and the drivers' unwillingness to get through too many sets of tyres that they might need later in the weekend if things stayed damp.
By far the biggest incident happened in the closing minutes, when Kamui Kobayashi ran wide out of the final corner, slewed left as his Sauber suddenly gripped on the run-off ara, then hit a bump on the grass and almost flipped before slamming into the barriers. He was unhurt, and the Sauber team did a spectacular job to repair the car for the afternoon.