Currently I'm doing a research on early-modern History in the city of Porto, Portugal. I'm very interested about demography- emigration- and what I wanted to do was to find Spanish people during the Iberic Union. However, the primary sources for the study of emigration in the early-modern era are very few. I started by the wedding records, but they were very disorganized and didn't give any useful information. The solution I found was the Hospital records (The source encompassing a larger universe of people, following the marriage records). Luckily I found 52 Spanish entering the Hospital from 1596 to 1598. Now I'm starting to write this project and it's time to do the data analysis.
On September 3rd of 1597 about 20 Spanish soldiers entered the Hospital. I need to know what caused this. I've been searching for a few weeks, alongside other relevant bibliography for this analysis, but I can't find anything. So, in short, do you know where can I find this information? Maybe some bibliography about military History in Porto? I've read History of Porto ("História do Porto", dir. Oliveira Ramos: basically the chapter about the XVI/XVII centuries is written by Francisco da Silva and it's similar to his thesis), The New Military History ("Nova História Militar" dir. Manuel Themudo Barata, Nuno Severiano Teixeira), a really good PhD thesis about Porto during the Iberic Union ("O PORTO E 0 SEU TERMO (1580-1640) -OS HOMENS, AS INSTITUIÇÕES E 0 PODER", by Francisco Ribeiro da Silva) and a lot more...