Michiel van der Leeuw • Link
Flushing was the birthplace of admiral Michiel de Ruyter (considered the greatest Dutch admiral ever), of whom we certainly will hear a lot in the next years.
S. Spoelstra • Link
Flushing had been an english foothold up to 1616. It was gouverned by Robert Sydney, Earl of Leicester.
"Flushing's strategic importance kept Sidney fully occupied but his view that nothing else mattered as long as Flushing was safe must have irritated those at home. He bombarded ministers with letters bewailing the lack of supplies and money."
In those days the town was a springboard for "undercover operations", maybe most famously the one involving Christopher Marlowe.
Looking at the number of mentions of Flushing in the diary in a short period of time maybe this practice is beeing taken up again.
A 1640 map of Flushing (Vlissingen), the harbor-city of Zeeland
(the map linked by Phil, alas, can no longer be found.)
Historical-political map of the low countries 1556-1648
(Zeeland is in the south, on the sea just north of Flanders. Middleburg is labeled, but its port, Flushing (Vlissingen) to its south, is not.)
Flushing, Netherlands Wikipedia article http://en.wikipedia.org/wiki/Vlissingen
Chart showing the number of references in each month of the diary’s entries.