Why did England and Spain go to war?

Spain (ruled by Philip II) and England (ruled by Elizabeth I) initially got on well.  Philip II was keen to marry Elizabeth.  There was friendship between the two countries.  However this friendship very quickly turned to tension and rivalry.  Eventually war broke out.  In July 1588, Philip sent a huge Armada of 130 ships and 30,000 men.

Yet what caused this initial friendship to turn to war?

Armada