Lisbon was rumoured to be guarded by a disaffected garrison. The English fruitlessly besieged Corunna, but the Spanish had spent a fortnight shoring up Portugal's military defences. When Norreys invaded Lisbon, the expected uprising was not forthcoming, and little was achieved. Drake took the opportunity on 30 June of seizing a fleet of 20 French and 60 Hanseatic ships, which had broken the English blockade on trade with Spain by sailing all around the north of Scotland, only to fetch up before the English cannon in the mouth of the Tagus. That seizure, notes R. B. Wernham, "dealt a useful blow to Spanish preparations",(p. 204) but later required a publicly-printed justification, a "Declaration of Causes", from the Queen's own printer since, without booty, she and her fellow English investors faced considerable losses.