I've got Fallout 4 on xbox one and i'm quite far into the campaign, I'm having an issue with moving the minutemen from sanctuary to the castle. I've completed the quest of retaking the castle. i've spoken to all of the settlers including Preston Garvy and there isn't an option for moving them.

Any help would be hugely appreciated!

You need to do it in workshop. When you look at your settler, there is a line on the bottom of the screen showing you what buttons to press to move your settler or to create a supply line. But not all npc settlers can be moved. Some named npc can`t be moved without using tricks or console commands.

So characters such as Preston Garvy can't be moved?

However when i open the map it still says the settlement is in sanctuary but on my friends game he's completely moved it to the castle; i was interested how you could completely moved it.

yeah like the other guy said, activate the workshop and then go to your settlers and you'll have the option to "move" them

okay cheers, i'll give this a go. Do i have to move so many settlers before the settlement moves on the map (like an automatic thing?).

It will move settlers, however anything you've built stays in place. You'll have both Sanctuary and The Castle as settlements, but your settlers will now be at The Castle. If you have a beacon up at either location it will draw in new generic settlers for you as well. (To make the beacon work you'll need a generator and connect it with a wire.)

Also I believe you need the first local leader perk.

So if I set up a beacon in both locations it'll make a sort of link?

Is that a VAT perk?

Sorry, but I think you just did not understand something. You can`t move settlements. You can move settlers and you can have many settlements in the same time. Radio beacons attract new settlers to your settlements ( so you can get more settlers).

You also can move settlers from one settlement to another ( in workshop mode). Number of settlers in one settlement is limited by your charisma.

If you have discovered some settlement and killed all enemies there, you can open it`s workshop and it will make the location your settlement.

And if you want to create supply lines between you settlements, you should take the "Local leader " perk.