Question: My coworker accidentally made two commits in the default branch instead of creating new his own development branch.

How can I change this situation and moves these two commits to a new branch?

Answer: 
### A major question

Have the accidental commits reached other repositories or is it just in his own? If so, you can skip to the section below 'Maybe the cat is still in the bag' otherwise you may have a fair bit of work to do.

**You are not alone**

See [here](https://stackoverflow.com/questions/2219756/how-to-move-some-changeset-to-a-new-branch-in-mercurial) for more discussion on how to correct the problem elsewhere on Stack Overflow. What is described is the 'proper' way to to it 

* export a patch
* create the branch
* import the patch
* delete the earlier commits.

**Maybe the cat is still in the bag**

If the changes are only in the local copy, then a simpler solution is to 

* create the new branch
* switch to it
* merge the changes onto that either with your fav merge tool ([go Meld](http://meldmerge.org/)) or with **hg graft**
* use the **hg strip** command to delete the changes on the old brach
* push the changes to the world
* pretend like nothing ever happened, whistle a happy tune ...
The two answers above are both correct but, **assuming one has not yet pushed the commits**, there's a third way.

I just successfully used the [`rebase`](https://www.mercurial-scm.org/wiki/RebaseExtension) command to move a string of commits to a topic branch I had forgotten to create in the first place.

I first updated to the revision from which I wanted to create the branch on which my commmits were supposed to be, then I rebased the earliest of my commits from the wrong branch on this new one and ta-da, done.

Takes more time to explain it than to do it with TortoiseHg or even the command line, really.