Team Banzai is trying to go have one more bit of fun before smacking back into the books!
Ooooh this is a complicated question you ask and it’s very difficult to answer shortly. Let’s see if I can answer this within a reasonable length. To start off, have a silly diagram on the relationships of the British Isles countries:
(and let me just make this clear, I put England in the centre since he is a canon character and not because he is superior to the others. I just felt it made the diagram clearer as well and not a mess of lines)
Green line = From good to really good relations
Blue line = Awkward, some past tensions but improving
Red line = It’s… complicated. Not at each other’s throats but a mix of teasing, awkwardness, past tensions, a little resentment… they do care for each other but are rarely obvious about it.
Pink/purple line = Neutral going on good? Not much interaction.
To go into more detail, I will first focus on England’s relationships with his siblings as they are probably the most complicated:
England and Ireland = They’ve had a violent and bloody history with each other so no doubt the relationship was extremely strained at times. However in early history, their relationship wasn’t awful, one could say they even got along. The relationship took a turn for the worst only in the last 3-4 centuries when England became obsessed with Anglicizing Ireland and Ireland violently rebelled and broke away from the UK. However many people have chosen to regard Ireland cuttng political ties (leaving the UK) as him cutting familial ties which I absolutely never agreed with. Family is important in Ireland and I strongly doubt Ireland cut familial ties with England and the others after he left the UK. (this is just a big personal peeve of mine) However after leaving there was probably resentment that remained between England and Ireland but over the years, their relationship has improved and the resentment is morphing into awkwardness. I like to regard their current relationship as awkward siblings “not exactly friends yet but no longer enemies”.
England and Scotland = To put it shortly, brothers with a long-standing rivalry. A lot of teasing, poking fun and arguing over who is better. Their relationship arguably wouldn’t have been as strained as it was with England and Ireland but it would be incorrect to assume that there wasn’t a good amount of anger, resentment and exasperation between Scotland and England. England was in the last few centuries leading up to recently obsessed with making his neighbours English and subservient while Scotland was concerned with remaining distinguishable from England and refusing to become anyone’s lapdog, especially an English one. So yeah, in the past there was certainly a lot of friction between the two and both were exasperated and angry with the other. Right now Scotland does probably feel resentment towards England’s government for having so much say in his affairs and would like more freedom. On a personal level, I think England and Scotland care for each other but are more likely to express it through teasing. (this is the reason why I really dislike the popular interpretaton of pixiv Scotland abusing the hell out of England)
England and Wales = I think of all the other countries in the British Isles, Wales probably holds the least amount of past resentment towards England. Not that there was no resentment at all but taking into account the other countries, Wales does appear to have the least strained relationship with England. Of course the main tension that existed between them was the recent cultural erasure that Wales suffered at England’s hands while England was obsessed with making everyone around him English. Apart from that, their relationship is not too horrible and is mostly peaceful nowadays. I don’t think it would be beneath Wales to occasionally join Scotland in teasing England but otherwise he is a calm and passive nation who works on the principle “You respect my privacy and I will respect yours.” I would think that England by now is more mindful about not stepping on Wales’ toes because although it is very difficult to have Wales become openly enraged, Wales knows how to be passive-aggressive to an uncomfortable degree.
England and Northern Ireland = A lot of people first assume that Northern Ireland and England have a pretty good relationship, which is not the best assumption to make. Perhaps at first when Northern Ireland was created by England, he might have looked up to England for guidance and protection and would have gotten along really well with him. But with the Troubles that happened from the late 1960s to 1998 in Northern Ireland, England screwed up many times in his attempts to help the younger nation. Northern Ireland has become a bit disillusioned with how he used to regard England and probably carries more recent resentment over England’s failure to help him effectively during the Troubles. England probably feels horribly guilty over all this but at the same time he is frustrated that his way of dealing with the Troubles didn’t work. I would mostly regard their relationship as being awkward with a hint of resentment, they still care about each other but there are sensitive topics they avoid talking about despite these topics being difficult to ignore.
…darn it, I did warn this would be difficult to answer shortly. I’ll try to sum up the other relationships very briefly, it will give you some space to research further. If there is a relationship you are stuck on, I’ll do my best to help.
Ireland and Scotland = These two get along really really well, it’s probably one of the more positive relationships in the British Isles. The relationship is not beyond flawless, there have been a number of hiccups n the past. But taking into account their historical, cultural and lingual closeness, it’s a relationship that I consider to be very positive. I will admit that I have a bias towards this relationship but it’s hard not to be after all the things I’ve read about them. There are a lot of common interests and cultural similarities in this relationship, I always was confused by the people who decided to interpret Scotland and Ireland as enemies since I feel the good things outweigh the bad in this relationship.
Ireland and Wales = Pretty good relationship, it might have started off with a few hiccups (the north part of Wales was invaded by the Irish tribe Laigin, the Llŷn peninsula in Wales is said to be named after them) but at present they get along very well with their shared interest in Celtic heritage and other things they share in common.
Ireland and Northern Ireland = Very awkward but improving relationship. Many people think Ireland would regard Northern Ireland as a stolen brother but I have a more cruel outlook on the relationship. I personally believe that Ireland spent a part of the 20th century regarding Northern Ireland as someone who didn’t need to exist. From the 1920s to the 1970s, most people in Ireland’s government called Northern Ireland “the six counties” and otherwise refused to use the real name. I think that would reflect on Ireland’s attitude, he thought that the people and land Northern Ireland represented was his by right and he blamed Northern Ireland for the Irish Civil War. Thankfully Ireland started changing his opinion around the second half of the 20th century and began accepting Northern Ireland as a brother, but his original attitude had caused a lot of damage to their relationship. So there is a lot of awkwardness between these two, arguments and getting defensive is not an uncommon occurrence. But their relationship is on the mend.
Scotland and Wales = I would class this relationship as quite good. Typically Scotland and Ireland have always paid attention to each other more than either have to Wales. However when these three are together, they get on really well. Scotland and Wales share similar political views and I would think they share quite a few common interests as well. It’s not unusual for them to team up together against England in an argument. There might be a few hiccups that occurred in the past between them, but not enough for their relationship to have problems today.
Scotland and Northern Ireland = Really good relations, being geographically close to each other has led to Scotland and Northern Ireland sharing a lot of things in common. They get along really well, perhaps even better than Northern Ireland does with England. (a possible source of jealousy)
Wales and Northern Ireland = A bit difficult to figure this relationship out since there is so little interaction between them. I consider it would be rather neutral going on good, I think they would generally get along.
Hope this helps you out, truly sorry for how long this has taken me to answer!