The amount of background information required will depend on the topic.
There should be enough background information so you don't have to spend too much time with it in the body of the thesis, but not so much that it becomes uninteresting.
While the body of your thesis will explain the main argument, you might want to lead into the thesis statement by briefly bringing up a few of your main supporting details.
Every paper you write should have a main point, a main idea, or central message.
Tip: In order to write a successful thesis statement: Your thesis statement should be as clear and specific as possible.
Normally you will continue to refine your thesis as you revise your argument(s), so your thesis will evolve and gain definition as you obtain a better sense of where your argument is taking you.
These points can help you write a good thesis introduction: Before even starting with your first sentence, ask yourself the question who your readers are.
Your first and most important reader is your professor grading your work and the people ultimately responsible for you getting your diploma.
The argument(s) you make in your paper should reflect this main idea.
The sentence that captures your position on this main idea is what we call a thesis statement.