Why did the creation of castles decline in the fifteenth century?

The development of firearms ended the castles' endurance. Another reason is when abandoned they could quickly be reduced to rubble by local people using them as a source of dressed stone and other building materials.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.