two title pages in the book without restarting the pagenumbering

Question

\documentclass[11pt,twoside]{book}
\input{Brillpreamble}
\begin{document}
\frontmatter
\include{titleBrill}
\include{abbrevBrill}
\include{prefaceandintroBrill}
\mainmatter
\input{./title1.tex}
\include{text1}
\input{./title2.tex}
\include{text2}
\backmatter
\printindex[nominum]
\printindex[rerum]
\pagestyle{myheadings}
\include{Biblio}
\end{document}

this is my preambleBrill code:

% XeLaTeX can use any Mac OS X font. See the setromanfont command below.
% Input to XeLaTeX is full Unicode, so Unicode characters can be typed directly into the source.

% The next lines tell TeXShop to typeset with xelatex, and to open and save the source with Unicode encoding.

%!TEX TS-program = xelatex
%!TEX encoding = UTF-8 Unicode

\usepackage{booktabs}
\usepackage{ledmac}
\linenummargin{inner}
\sidenotemargin{outer}
\usepackage{fancyhdr}
\usepackage{adforn}
\usepackage{amsmath}
\usepackage{lmodern}
\pagestyle{myheadings}
\usepackage{hanging}
\usepackage{pdfpages}
\textheight = 180.5 mm
\textwidth = 108.5 mm
\pagenumbering{arabic}
\usepackage[hang]{footmisc}
\setlength{\footnotemargin}{12pt}
\makeatletter
\renewcommand\@makefntext[1]{%
  \noindent\makebox[1em][r]{\@makefnmark}#1}
\makeatother
\usepackage{imakeidx} 
\makeindex[name=nominum, title=Index nominum, columns=2]
\makeindex[name=rerum, title=Index rerum, columns=2]
\pretolerance=100
\usepackage{microtype}
\makeatletter
% And in the paragraphed footnotes, I'd like no colon too:
\def\parafootfmt#1#2#3{%
  \normal@pars
  \parindent=0pt \parfillskip=0pt plus 1fil
  {\bf\printlines#1|}%
  {\select@lemmafont#1|#2}~%
  #3\penalty-10 }
\makeatother
\let\Afootfmt\parafootfmt

%\newcommand{\rhet}[2]{\edtext{#1}{\Afootnote{#2}}}
\newcommand{\rhet}[2]{\edtext{ #1}{\Afootnote{] #2}}}
\newcommand{\oed}[2]{\edtext{ #1}{\Bfootnote{] #2}}}
\footparagraph{A}
\footparagraph{B}

%%%%%%%%%%%%%%%%
\raggedbottom


\newcommand*{\LeftWidth}{3.0cm}%
\newcommand*{\RightWidth}{\dimexpr\linewidth-\LeftWidth-2em\relax}%
\newcommand{\AlignedBrace}[2]{%
    \medskip\par\noindent%
    \parbox{\LeftWidth}{\raggedleft\textbf{#1}\strut~}%
    $\left\{~\parbox{\RightWidth}{\strut\textit{#2}\strut}\right.$%
}%


%\usepackage{geometry}                % See geometry.pdf to learn the layout options. There are lots.
%\geometry{a4paper}                   % ... or a4paper or a5paper or ... 
%\geometry{landscape}                % Activate for for rotated page geometry
%\usepackage[parfill]{parskip}    % Activate to begin paragraphs with an empty line rather than an indent
\usepackage{graphicx}

\usepackage{amssymb}
%\renewcommand %These two commands are for double-spacing
%\baselinestretch{2}

% Will Robertson's fontspec.sty can be used to simplify font choices.
% To experiment, open /Applications/Font Book to examine the fonts provided on Mac OS X,
% and change "Hoefler Text" to any of these choices.

\usepackage{fontspec,xltxtra,xunicode}
\defaultfontfeatures{Mapping=tex-text}
\setromanfont[Mapping=tex-text]{Brill}
\setsansfont[Scale=MatchLowercase,Mapping=tex-text]{Gill Sans}
\setmonofont[Scale=MatchLowercase]{Andale Mono}
\frenchspacing

\newfontfamily{\H}[Scale=0.9]{Lucida Grande}
\usepackage{caption}
\captionsetup{aboveskip=5pt}

\def\changemargin#1#2{\list{}{\rightmargin#2\leftmargin#1}\item[]}
\let\endchangemargin=\endlist

Answer 1

The problem with \maketitle is, that it is a command that disables itself after being called by using \global\let\maketitle\relax (the same is true for \title, \author etc.

This can be disabled either be redefining \maketitle or using \xpatch and removing the relevant code.

This will prevent the restart of the pagenumbering anyway.

The next culprit is that book uses titlepage implicitly. If this option is used, the maketitle uses \begin{titlepage}...\end{titlepage} which will automatically reset the page number.

I provide the notitlepage version here for the moment and try to get the titlepage beast later on.

\documentclass[notitlepage]{book}



\usepackage{xpatch}

\newcounter{titlescntr}

\makeatletter

\xpatchcmd{\maketitle}{\par
}{%
  \par%
  \stepcounter{titlescntr}
  \ifnum\value{titlescntr} > 0 
  \cleardoublepage
  \fi
}{}{}

\xpatchcmd{\maketitle}{%
  \global\let\thanks\relax
  \global\let\maketitle\relax
  \global\let\@maketitle\relax
  \global\let\@thanks\@empty
  \global\let\@author\@empty
  \global\let\@date\@empty
  \global\let\@title\@empty
  \global\let\title\relax
  \global\let\author\relax
  \global\let\date\relax
  \global\let\and\relax
}{%
  \clearpage
}{\typeout{Patched!}}{\typeout{Patching failed!}}

\makeatother

\title{Two treatises} 
\author{Guillaume Coatalen} 
\date{} 

\usepackage{blindtext}

\begin{document}

\maketitle 

\title{Theory of Brontosaurs}
\author{Ann Elk}
\maketitle

\blindtext


\end{document}

Updated: Removing the resetting of the page number if titlepage is used

\documentclass[titlepage]{book}
\usepackage{xpatch}
\newcounter{titlescntr}

\makeatletter

\if@titlepage
\xpatchcmd{\maketitle}{%
  \global\let\thanks\relax
  \global\let\maketitle\relax
  \global\let\@thanks\@empty
  \global\let\@author\@empty
  \global\let\@date\@empty
  \global\let\@title\@empty
  \global\let\title\relax
  \global\let\author\relax
  \global\let\date\relax
  \global\let\and\relax
}{%
}{\typeout{patched maketitle for titlepage}}{}

\xpatchcmd{\titlepage}{%
  \setcounter{page}\@ne
}{%
}{\typeout{patched titlepage}}{}

\xpatchcmd{\endtitlepage}{%
  \setcounter{page}\@ne
}{%
}{\typeout{patched endtitlepage}}{}

\else

\xpatchcmd{\maketitle}{\par
}{%
  \par% 
  \stepcounter{titlescntr}
  \ifnum\value{titlescntr} > 0 % Make a new page for the next title
  \cleardoublepage
  \fi
}{}{}

\xpatchcmd{\maketitle}{%
  \global\let\thanks\relax
  \global\let\maketitle\relax
  \global\let\@maketitle\relax
  \global\let\@thanks\@empty
  \global\let\@author\@empty
  \global\let\@date\@empty
  \global\let\@title\@empty
  \global\let\title\relax
  \global\let\author\relax
  \global\let\date\relax
  \global\let\and\relax
}{%
  \clearpage
}{\typeout{Patched!}}{\typeout{Patching failed!}}
\fi

\makeatother

\title{Two treatises} 
\author{Guillaume Coatalen} 
\date{} 

\usepackage{blindtext}

\begin{document}

\maketitle 

\title{Theory of Brontosaurs}
\author{Ann Elk}
\maketitle

\blindtext


\end{document}

Answer 2

I'm lazy. If somebody else has already done the work and I can use theirs, I figure there's no need for me to spend time poring over different designs for the newfangled invention they call a 'wheel'.

---

I would use etoolbox to patch the titlepage environment which book uses for titles by default, and let titling do the rest.

\usepackage{etoolbox,titling}
\makeatletter
\patchcmd{\titlepage}{\setcounter{page}\@ne}{}{\message {Successfully patched titlepage.}}{\message {Failed to patch titlepage.}}
\makeatother

The patch simply stops the use of titlepage by \maketitle from restarting the numbering scheme. However, we'll still get numbering from 1 when we first switch to Arabic numerals in the main matter because \mainmatter takes care of that automatically.

Loading titling allows us to use the regular \title, \author, \date, \maketitle commands as many times as we like in the document.

\title{Title 1}
\author{Author 1}
\date{Date 1}
\maketitle

\title{Title 2}
\author{Author 2}
\date{Date 2}
\maketitle

[I'm not against the use of \maketitle although it can, obviously, have unwanted effects when misunderstood and is, perhaps, unfortunately named. In any case, since it is easy to use and keeps my code here simple, I would see no reason to look a gift horse in the mouth, even if I had general doubts about the horse's value in other contexts.]

Because you are already using \frontmatter and \mainmatter, there's no need to worry about setting the kind of page numbering as the book class uses lower-case Roman numerals for the front matter and Arabic numerals for the main matter by default.

\frontmatter

switches to lower-case Roman numerals, starting from 1.

\mainmatter

then switches to Arabic numerals, restarting the count from 1.

Complete code:

\documentclass[11pt]{book}
\usepackage{etoolbox,titling}
\makeatletter
\patchcmd{\titlepage}{\setcounter{page}\@ne}{}{\message {Successfully patched titlepage.}}{\message {Failed to patch titlepage.}}
\makeatother
\pagestyle{myheadings}
\usepackage{kantlipsum}
\begin{document}
\frontmatter
\kant[1-5]
\mainmatter
\title{Title 1}
\author{Author 1}
\date{Date 1}
\maketitle
\kant[6-10]
\title{Title 2}
\author{Author 2}
\date{Date 2}
\maketitle
\kant[11-15]
\backmatter
\kant[16-20]
\end{document}