The Earth is tilted 23 1/2 degrees on its axis. The direction of the Earth's tilt does not change throughout its orbit.

At which position of Earth is it summer in the Northern Hemisphere?

It is useful for historians to write narratives so that history can be passed on from their point of view.  think about a story being told in third person, then think about it again being told in first person, by someone who actually experienced the event.