How do you make a thesis about the history of something?

Writing a thesis about the history of something is not
particularly difficult since it will probably fall naturally into some kind of
chronology.  A thesis generally contains three main points outlined in a sensible
order.  Consider several options for, let's say, writing about the history of the
pencil.

One option is to literally start with the first
crude version of the pencil up to the present-day mechanical pencil.  Break the time
line down into three periods and go from there.

Another
option might be to start with the original lead pencil and then give two major
improvements which have been made to improve this writing device (for example, using
graphite and the mechanical pencil).

You might also select
the parts of the pencil (lead, wood, eraser) and discuss the changes which have been
made over time in each part. 

An historical event can be
divided by years, by key moments, or by people who had an impact.  A biographical
history can be divided by years or stages of life.  Really, anything historical can
always be dealt with chronologically, and that's where I'd begin.  Best of
luck!