 Complete the following phrase:  The invasion of the Napoleonic troops in Portugal under Marshal Soult brought war to the city of Porto. On 29 March 1809, as the population fled from the advancing French troops and tried to cross the river Douro over the Ponte das Barcas a pontoon bridge, the bridge collapsed under the weight. This event is still remembered by a plate at the Ponte D. Luis I. The French army was 