On 17 September, Battle of Britain Day, supporters blocked the pierheads at Holy Loch and the approaches to Trafalgar Square. (Picture) The September demonstration is regarded as the high-water mark of the Committee of 100. A week before the demonstration, the hundred committee members were summoned to court without charge under the Justices of the Peace Act of 1361 because they "incited members of the public to commit breaches of the peace" and were likely to continue to do so. The court bound them to a promise of good behaviour for twelve months; thirty-two, including Bertrand Russell, then aged 89, refused and chose to go to prison instead. It is estimated that 12,000 to 15,000 attended the demonstration despite the invocation of the Public Order Act, which effectively made it illegal to be in the vicinity of central London that day. Several thousand sat down and there were 1,314 arrests, but no violence from demonstrators despite allegations of police brutality.