Henri Grace a Dieu

Henry Grace à Dieu by Anonymous
Source: wikimedia commons

13th June 1514, Woolwich Dockyards, London. King Henry VIII flagship, Henri Grace a Dieu, was launched and became the most advanced, biggest (50m long) and heavily armed (43 cannons) warship carrack in the world at that time. "Great Harry" (as nicknamed) was first ship build in Woolwich Dockyard. First Royal dockyards were built at Portsmouth during Henry VII reign with the main purpose to build trade ships. Henry VIII had different priorities - threats from France and Spain make it essential to building warships. Woolwich and Deptford are located close to London, at Thames river.

"(...) there was a threat of war from England's Catholic neighbours, France and Spain. Portsmouth was a long way from the Armouries in the Tower of London, where all ships were equipped with cannon and artillery. To make the building of warships more convenient, Henry decided to build two dockyards on the Thames in 1513. These would be close to London where it was easier to get arms, supplies for building the ships and a ready labour force. Henry chose Woolwich and Deptford as his sites as they were also conveniently near his Palace at Greenwich, which meant that he could watch the shipbuilding in progress." Source: The Royal Dockyards of Deptford and Woolwich 

The Sicilian Vespers

Peter III (second from left in upper boat) invading Sicily
Source: wikimedia commons

King Peter III of Aragon coronation as Peter I was result of Sicilian uprise against French despot Charles of Anjou. French rules in Sicily were very unpopular so when during vespers of Easter Monday, March 30th, 1282 at the Church of the Holy Spirit group of French soldiers join Italian crowd during local wedding. His misbehave cause anger eruption in local people. Angry crowd kill him and other soldiers. This bloody event start uprising that end with numerous killed French soldiers and Sicilian inhabitants.
This event gave Peter opportunity to invade Sicily to claim his rights to throne, which happened on February 2nd, 1283
Peter's wife Constance, heir of Holy Roman Emperor Frederick Barbarossa. That's make additional threads for papacy already frightened by powers of German emperors. To counterweight it pope Martin IV support French king and therefore also Charles as Sicily ruler. However Martin don't know that Peter had built his fleet with strong financial support from East Roman Emperor Michael Paleologos. Martin dream was to unite west and east church but wasn't aware about plans of his ally Charles who plan to used fleet build using pope money to conquer Constantinople although officially build for next Crusade against Islam.