Viking invasions started in around 790 AD. In 793 the monastery at Lindisfarne was attacked. Churches were an easy target for the Vikings as they were built in remote locations and were poorly protected. Most importantly they contained ornaments made of silver and gold. The Vikings killed the monks and burnt the buildings. The monastery of Iona on the west coast of Scotland was attacked in 802 AD.
What started as a land dispute between Owen Glendower, a wealthy land owner in Wales and his rival Lord Grey of Rutin quickly escalated to a revolt when the English King Henry IV sided with Rutin and awarded him the land.
The battles of the War of the Roses took place between 1455 and 1487. The war was fought between supporters of several descendants of Edward III, the King of England from 1327 to 1377. The war was not a constant fight that affected the whole country and its population, but a series of battles spread out over the years between sets of supporters known as the Lancastrians and the Yorkists. Some of the battles were fought by thousands of men. The Battle of Towton being the largest and the bloodiest.