A Spanish Attack on Portugal. Report by J.I.C.

(e) Speed of Advance 9. This would naturally depend on the degree of Portuguese resistance. We assume that the Portuguese forces opposing the thrust to Lisbon would amount to some six regiments, which are equipped on about the same scale as the Spanish army. Poor communications and inadequacy of supplies would also slow down the advance. Unless Portuguese resistance collapsed, the Spanish forces would be unlikely to advance more than ten miles a day. In the worst possible case for the Portuguese the Spaniards might reach Lisbon in a fortnight to three weeks from the time of crossing the frontier.