How-to add preface into book generated by Python Sphinx from reStructred files set

Question

I have a set of rst files that should be combined into one book (PDF or HTML) for example

Preface.rst Chapter1.rst Chapter2.rst

etc.

Chapter file starts from header like:

Chapter 1

Preface starts from header too.

Preface

After generation by command : sphinx-build ${build_options} -b latex "${src_dir}" "${target_dir}/pdf"

I see TOC with item :

• Preface in document body that has header Chapter 1
• Chapter1 in document that has header Chapter 2 etc.

I would like

• Preface in document body without additional header Chapter 1
• Chapter1 in document that has header Chapter 1

etc.

What way is able to help me to reach this target