Why did the Spanish Armada fail?

      Secondly, the use of Fire ships. The English launched fire ships at the anchored Spanish fleet, which scared the Spanish captains enough to make them cut their anchors and try to avoid the burning ships. Not many Spanish ships were lost, but the Spanish formation was broken up, and the Armada would be in some mess by the battle of Grave lines.     

      Battle of Grave lines. This would be the decisive battle for the English, an attempt to put an end to the Spanish threat. Holding the weather vane, using standoff tactics and superior gunnery, The English were able to inflict a defeat on the Spanish. The defeat was in reality not that big, with the Spanish losing only a handful of ships. But it completed one critical, though unrecognized advantage. The Spanish were pushed up along the east coast of England, unable to simply turn back and sail back down the channel. Wind and current meant that the Armada's only choice would be to sail all the way up around Scotland, and eventually down the coast of Ireland to return home.     

      Last but not least, they were failed also because of the weather. Once forced to commit to sailing around England, the Armada was doomed. The place is infamous for its weather, and the Spanish Armada would end up sailing north and into one of the storms of that place. It was the weather that would inflict the most injuries on the Spanish fleet, sinking or driving on land almost half of those ships. Thousands of Spanish sailors would die, and the balance of power on the seas would shift from then out to the British.

      Overall, I think that the most important reason was the fire ships. Since it was the only one that could make the Spanish Armada’s formations to be broken up and so it could let them be messed up.