Not only do you need to hook a reader quickly, but also you need to keep them involved in the story. Part of doing so involves your creation of a believable “world” for the story.
A story world includes the minute details of where and when the story takes place. Think about the world around you right now. What do you see? What do you hear? What do you smell? What do you feel when you touch certain items around you? And even what can you taste in the world in which you live?
Your story’s world (no matter what time period) should make the reader “see” through the character’s eyes, experience everything through the character.
In whatever time period and story world you are creating, you need to understand, and let the reader understand, how things were then or are now. What were the cultural mores, social customs, politics, and religious influences? What level were they at as far as techology? What would commonly have been found in their architecture, furnishings, and transportation? What were the common roles of women or men? What were the typical types of occupations? What was going on in their world at that time: wars, explorations to new places, and education? What did they eat? What did they wear? How did they speak? What slang words were commonly used?
I have added my list of links for Building a Medieval Story World to the Writing Tips on this blog and to my Writing Tools on my website. Even if you don’t write in that time period, there are some very interesting links here. I hope you take a few minutes and explore them.