What day of the week was August 4, 1578?

The day of the week August 4th, 1578 fell on was a Friday.

Sebastian of Portugal (b. 1554) died on this day in 1578. As did Thomas Stukley the English mercenary (b. 1520) .

Battle of Al Kasr al Kebir the Moroccans defeat the Portuguese. King Sebastian of Portugal is killed in the battle the leaving his elderly uncle, Cardinal Henry, as his heir. This initiates a succession crisis in Portugal.