Itinerary for 21-day rail trip thru England, Ireland, Scotland

London and other parts of England are well-connected by rail to Edinburgh and other major Scottish cities, although on our trip last month we took a fast, cheap flight between the two capitols, and then had a rental car for much of the time. Depending on how much of Scotland you're planning to visit, some parts aren't served as well by rail, and you might want to look into bus (coach), rental car, or hired-tour for parts of your itinerary. On Skye, for example, once you're on the island, having your own set of wheels, or having someone else driving the roads, allows you maximum flexibility for timing and experiences.

On a trip years ago, we took a train from London to Edinburgh for a few days, then stopped for a few days in York, before returning to London and our flight back to the USA,

We LOVE traveling England and Scotland (and parts of Wales) by train! We never had such a long time, but I'll share what we did and try to give you some time estimates:
fly into London- spend 4-7 days (LOTS of day trips by train possible- including: Bath, Cardiff, Canterbury, Dover, Stratford-upon-Avon, Winchester, Brighton, Oxford, Cambridge, Windsor and many other places)
Train to York (~2 hours)- spend 2-4 days
Train to Edinburgh (~ 2hours)- spend 3-4 days
Train to Aviemore (~1 hour)- 3-5 days - lots of GREAT distilleries and other things to do)
Train to Inverness (~ 1 hour)- 4-7 days-(lots of good day trips here, too including Isle of Skye and Elien Donan Castle, long one to Orkney, Glen Coe, Great Glen, Ft Augustus, Ft William...)
Train to Glasgow ( not sure of train times)- 2-4 days
then you could train into Wales or back into England....

Thank you. Both above answers very helpful.

I think Toni above has a great itinerary set up for you!

For a rail route tour of Britain, staying at places along the way, I would do :>
Land at Heathrow - shuttle bus to Woking for train to Salisbury (2 or 3 nights if you wish to make a day trip to Portsmouth Harbour), > Bath* (2 nights or 3 nights if you wish to make a day trip to Oxford) > Cardiff (2 or 3 nights) > Ludlow (no overnight - wander around for an hour or two) > Shrewsbury ( another wander?) > Aberdovey (1 night) > Porthmadog (2 nights - see Portmeirion) > leave on Welsh Highland Railway http://www.festrail.co.uk for Caernarvon (see Castle) then bus to Bangor and on to Conwy or Llandudno (bus or train). Conwy /Llandudno (2 or 3n) - see Bodnant Gardens & Conwy Castle.
* Bradford-upon-Avon might be a cheaper alternative & take the short train ride into Bath.
Now back to England with 1 night in Chester. Then Chester to Scotland (Glasgow or Edinburgh). A car would be handy in the Scottish Highlands but train routes do exist as previously mentioned). I will leave you to figure that one out.
Leave Edinburgh going south on the East Coast Mainline to York (2n). Then, to Cambridge (1n) & finally back to London.

Google places mentioned for more info.
www.nationalrail.co.uk (Advance book longer journeys for cheapest fares).
www.britrail.com
http://www.splityourticket.co.uk

Little pre-holiday research which will make travelling around by rail more interesting if you like that sort of thing: see if you can whistle up a copy of Great British Railway Journeys boxed set on DVD.