I have a site with multiple languages organized as follows: Multiple top level nodes, each with Domain (under Culture and Hostnames) set to www.mydomain.com/lang, where "lang" is the two-letter language code. One of them is English i.e. www.mydomain.com/en.

Now my situation is that the site responds to both www.mydomain.com/somepage and www.mydomain.com/en/somepage. This is fine, but what is not so good is that it leaves the URL in the request as is, which results in the same content rendered from two different URLs. Which is not good for SEO.

I'm not exactly sure how it became like this, but what I'd like to do now is to redirect all root domain requests (with subpaths) to one with the /en subpath. I.e. www.mydomain.com/somepage -> www.mydomain.com/en/somepage.

The other solution, which was my first thought, is to use the root domain only for English, and remove /en from the Domain setting. But, Google has indexed a lot of my pages using the /en subpath, so all these links will then end up in a "Page not found". I know that using the root domain only for English could be better for SEO, but how can I then get a general redirect from the /en requests to root domain requests and have Google update its indexing?

Any ideas and advice will be much appreciated!