Full page figure not in its place in cover page

Question

I used at the very beginning of my document "thesis":

\begin{figure}[p] \vspace*{-2cm} \makebox[\linewidth]{ \includegraphics[width=1.3\linewidth]{images/sequence2.pdf} }\end{figure} 

to insert the cover page of my thesis. The problem is that, in the PDF, this page is becoming page 2 while the "usually second page" acknowledgement becomes page 1.

Is there a way to force the page of the cover to be the first in the document or to stop changing the places of the two pages?

Answer 1

The following will work unless the inserted image is also too tall for the text block:

\documentclass[a4paper]{article}
\usepackage{geometry}
\usepackage{graphicx}
\begin{document}
\begin{titlepage}
  \centering\makebox[\linewidth]{\includegraphics[width=1.3\linewidth]{example-image-a}}
\end{titlepage}
\end{document}

Otherwise, possibly something like:

\documentclass[a4paper]{article}
\usepackage{geometry}
\usepackage{graphicx,calc}
\begin{document}
\begin{titlepage}
  \centering\vspace*{.5\textheight}\makebox(0,0)[]{\includegraphics[width=1.3\linewidth]{example-image-a4}}
\end{titlepage}
\end{document}

Answer 2

Since you are keeping us guessing, here is a near-real document:

\documentclass[11pt,oneside,a4paper]{book}
\usepackage{makeidx,nomencl,graphicx,tikz}
\pagestyle{plain}
\begin{document}
\baselineskip = 17pt  %set line spacing to 1.5B

\begin{titlepage}
\tikz[overlay, remember picture]{%
\node at (current page.center){%
\includegraphics[width=\paperwidth,height=\paperheight]{example-image}};}
\end{titlepage}

\frontmatter
\chapter{Acknowledgement}
\chapter{Abstract}
\tableofcontents
\addcontentsline{toc}{chapter}{Contents}
\listoffigures
\addcontentsline{toc}{chapter}{List of Figures}
\chapter{Acknowledgement}

\mainmatter
\chapter{How to use the Thesis Template}
\section{Introduction}
\section{Footnotes}
\section{Splitting the input}
\appendix
\chapter{Example Appendix}

\end{document}