How can I get extra subtitles for chapter titles that also appear in the ToC?

Question

I have several chapter titles that I would like to combine with subtitles, typeset in italics.

For example,

Chapter Title

A very fine chapter indeed …

Now, I found an approach on how to do this here, introducing a new \Chapter command, which now looks like this:

\newcommand\Chapter[2]{
  \chapter[#1: {\itshape#2}]{#1\\[2ex]\Large\itshape#2}
}

This somewhat works (although it breaks TextMate's auto-recognition of chapters), but I would like these subtitles to also be visible in the Table of Contents.

Like so:

Chapter Title                                                                                1

A very fine chapter indeed …

Is there any way to achieve that? Note that my LaTeX fu is pretty limited, so I'm not sure where to even start.

Answer 1

This simple solution should work for you. It is not formatted as you wished, but I really cannot imagine a ToC with subtitles below some title there.

\documentclass{report}

\newcommand\Chapter[2]{
  \chapter[#1: {\itshape#2}]{#1\\[2ex]\Large\itshape#2}
}

\begin{document}

\tableofcontents

\Chapter{My chapter}{Nice subtitle}

Lorem ipsum ...

\chapter{Another chapter}

Lorem ipsum ...

\end{document}

Alternative definition of \Chapter to have the subtitle below the title in ToC:

\newcommand\Chapter[2]{\chapter
  [#1\hfil\hbox{}\protect\linebreak{\itshape#2}]%
  {#1\\[2ex]\Large\itshape#2}%
}