Where to make a home base for 4 months to see Europe

Your interest area takes in about 2/3 of Western Europe.

If you want to visit Ireland, you are going to have to fly there. When we go to Europe, we never fly within Europe. We always tailor our trip to be in a more limited area.

You can spend a month and any one country like Italy, Spain/Portugal, France, Germany. Austria/Switzerland, Czech Republic/Poland, Croatia/Slovenia.

For Italy, I suggest somewhere in Tuscany. Florence is wonderful. For Spain and Portugal, Madrid would be an good option. For Spain and France, Barcelona would be great. For France, so many great choices, consider the Alsace region near Germany. Strasbourg would allow you to visit Switzerland, the Black Forest of Germany, the Rhine River area of Germany, as well as northern and eastern France (going down to Provence).

We love the UK and you could easily spend a month touring England and Wales. Add two weeks and include Scotland. A great base would be York.

The first thing folks here will ask you is are you aware of the 90 day Schengen rule for visitors with US passports? If you spend time in Ireland and Great Britain they are not included in the 90 day rule. Croatia is not in yet but will in the future.

https://en.wikipedia.org/wiki/Schengen_Area

To me this area is too big for "one" home base. I'd say you need to have several bases for week or two stays. You'd want to pick somewhere that is both of interest to you and that has good rail connections.

Are you familiar with the Schengen agreement? https://travel.state.gov/content/travel/en/search.html?search_input=schengen&data-sia=false&data-con=false&search_btn=

Steve: first of all remember the Schengen Area and the 90 day rule with all of its intricacies! You are going to need to think about multiple home bases for your trip. There are are multiple threads on this subject, just type Schengen in the search box and you will get a lot of information.

Are you open to multiple home bases? Will you be working remotely or are you free to travel full time for 4 months? Finally, what season?

I am assuming that you have already dealt with the time restriction imposed by Schengen in your trip planning. That part of the trip from Sweden to Croatia I would not have a home base, don't need it if you plan carefully. It sounds like a very good trip indeed.

I only travel using trains (day and night) and buses and ferries but no flying. Like you, no driving . When exactly? I prefer the summer, say from May to the beginning of Sept.

When asking about a home base I always assume the poster is expecting to do a bunch of day trips. If that is true for you, you are going to need multiple bases. If you are not going to do many day trips, why have a base at all? If you should reserve a base for weeks and find you do not like the base lodging, you will be stuck for weeks. Also, have you traveled for months at a time? It is much different than a few weeks.

We like to stay in cities that are in close proximity to each other, and those that have good airports and great train service. Then go on to another area.

I'm talking taking 3 cities over a 2 week, 3 weekend time period. Like Budapest, Vienna, Prague. Or, Munich, Salzburg, Vienna. Or, Rome, Florence, Venice. Or, Madrid, Granada, Barcelona. Or, London, Paris, Barcelona. We've long ago found that we can see so much more by traveling slowly.

Mix in a one week cruise around the Greek Islands and the Adriatic and you've got a great trip. Or, take a cruise to the major Scandinavian cities.

If you want to visit Ireland, you are going to have to fly there.

This is not true. From France, for example, there are ferries from Cherbourg to Dublin and from Roscoff to Cork. Possibly others, but those are the ones I'm familiar with. You'd have to really like boat travel, though, because they're not quick.

And, of course, if one wants to go to England first and then to Ireland, I'm sure there's numerous ferries that could get you there once you get to the correct departure port.

Ferries to Ireland, SLOW and EXPENSIVE

Dramamine.

From France there is also the ferry line from St. Malo to Portsmouth. Over a decade ago, when I was planning the first post-retirement trip , a good friend of mine in Ireland recommended the ferry link Roscoff to Cork.

You need to figure out a means of transportation once you arrive at your home base. I know you said no car. Really. Do you know all the choices of transport in the different cities you will home base in. Think about it. Trains are great but not so much in Ireland. Croatia, also not so good. Etc, Etc.

I would suggest given this 4 month trip duration that you research all varied transport options you have, aside from the train, (day and night trains) , buses, EuroStar (depending on your final itinerary), and the numerous ferry lines and routes. I have no problems taking ferries and can well understand your decision on rental cars....I wouldn't either, just depends on the extent of the final itinerary and travel style.

How are you going from Sweden to Croatia? Through Germany or by way of Poland? Keep in mind that ferry connections link Sweden to Poland. Night trains connect Croatia too.

Also be aware Croatia is slated to be a Schengen zone member beginning Jan 1 2023.
( https://vlada.gov.hr/news/no-doubt-about-eurozone-membership-decision-on-entry-into-schengen-area-can-be-expected-in-autumn/35647 )

Ireland is the only non Schengen country on your list.

The limit is 90 days, not 3 months.

A travel planning aid --- https://ec.europa.eu/assets/home/visa-calculator/calculator.htm?lang=en

Haven't seen Steve the OP since the question was first posted in August.

I guess we'll never know