What if gunpowder was discovered by the English instead of the Chinese?

With fire arrows and gunpowder propelled projectiles on their side from around the early 10th century, how would the history of Britain have changed with this new technology on hand to repel Viking invasions? How would it have affected the battle of Hastings? And would there be lasting affects to the modern day?

Similarly, how would China look today without their superior firepower in the early 10th century?