Table of content
Introduction
Chapter 1
Chapter 2
...

begin{document}
include{chapters/titlepage}
frontmatter

%Thesis Body
include{chapters/acknowledgements}
include{chapters/summary-es}
include{chapters/summary-en}

%Index
tableofcontents

%Chapters
mainmatter
include{chapters/introduction}
pagestyle{headings}
include{chapters/chapter1}
include{chapters/chapter2}
include{chapters/conclusions}

appendix
include{chapters/appendix}

backmatter
%Bibliography

end{document}

chapter*{Introduction}
addcontentsline{toc}{chapter}{Introduction}