Is it possible to merge two completely different branches?

[Alexander Belchenko]

I have two independent branches with different files and with
independent history. I.e. they have no common files, no common history.
Now I want to merge second branch into first one.

When I simply run merge I've got:
bzr: ERROR: Branches have no common ancestor, and no base revision
specified.

How to make this operation and have a chance to keep history of merged
branch? Is it possible?

Sorry if this question is stupid.

--
Alexander