Is a political union the only union that allows one country to be another's guarantor?

Question

Editing this question to word it better.

I don't know if it's a unique dilemma or a silly premise, but it looks like I need more guidance than I thought. I'm not a history buff and kingdom/state dynamics are all new to me, but I still wanted to have a go at it.

Although the setting takes place in the 19th century, the universe is quite fairy tale, so the reality is an alternate one with many liberties and laws that only apply to its fantasy kingdoms. It nonetheless mirrors much of the 1707 Act of Union for the creation of Great Britain:

Country A is on the brink of bankruptcy and, much like Scotland, hopes to be pulled up by the more powerful Country B on account of being plugged into Country B's economy, international trade, and the like. Country B is their only parachute; there are no other willing saviors. Country B is also quite kipper about having some dominance over Country A.

But it is possible for these economic aspects to be shared through a union that is NOT a political one that unites two kingdoms and their parliaments? Like an economic union (Benelex Union), some form of devolution, a dual monarchy, or a commonwealth?

Or is the best way to become economically stronger as part of Country B's economy a political union?

(Wince) I should add that there is a marriage involved between the two monarchs reigning in both fantasy countries, who reign under constitutional monarchies. Coregency/joint sovereignty were RL things depending on the countries https://en.m.wikipedia.org/wiki/Coregency (rare situation, though), and in most cases the queen still wasn't equal to her hubby, except perhaps in the case of Isabella of Castile and Ferdinand of Aragon (?) or Mary I and Phillip II (their contract suggests joint reign that suppressed Phil), but I know a unitary state has never occurred unless a child inherited both crowns. However, since Country B wants control of Country A's bank management and government spending, I don't know what kind of Union could grant that power unless it's a political union.

For some background, monarch A and B, both childless and threatened by bloodline extinctions, (if neither have legit kids their enemies will seize power) are NOT heads of government, so with or without the marriage, the economic desires above still apply.

So there are two deals to be secured, but because I'm iffy about whether a full-fledged U.K. is reasonable (even if this is fantasy), I wondered if any other unions could guarantee the same equal privileges as a political union in regards to the economy boost, bank control, and sharing trade partners and treaties with foreign powers. If not, I guess I have to go with a political union if any of you would find that tolerable as a reader.

This scernario is still open for anyone to hop on. You guys have been brilliant so far!

Answer 1

It should be like the union of Castile and Aragon

The situation that might be closest to what you are talking about it the merger of Castile and Aragon with Isabella and Ferdinand. The two kingdoms were both among the largest in Europe. The only difference was that Isabella was not ruling when the marriage took place, so they had time to get accustomed to the idea that they were ruling together. Isabella was about a year older than Ferdinand and was 23 when she became queen. Ferdinand was already king of Sicily upon marriage and became king of Aragon five years after Isabella got her crown, in 1479.

Isabella's predecessor as monarch was Henry the Impotent, which says most of what needs to be said. When she came to the throne in a disputed succession, there was an immediate rebellion by her niece, Juana, who was daughter of the last King. She was conveniently married to the King of Portugal, so Castile was split down the middle in loyalties, with Aragon supporting Isabella and Portugal supporting Juana. Ferdinand, as Consort of Castile, led the Castillan armies and did a generally good job. His strong support for her probably cemented their marriage and political alliance, and they reigned very successfully for thirty-odd more years.

In general, Castile was the larger and more populous state, but had been ravaged by civil wars and rebellions for most of the past century. Aragon, on the other hand, was nearing then end of a century long Golden Age and at the height of its commercial prowess in the Mediterranean. It controlled southern Italy and Sicily (mostly), Corisca, Sardinia, and Malta. Barcelona and Valencia were large, rich cities, as were Naples and and Palermo in the Two Sicilies.

In short, Castile was large and populous, with lots of resources, but with no large cities and a surfeit of rebellious nobles, roving mercenary bands, and recalcitrant Moors. Aragon was probably just as populous, considering its overseas territories, and was one of if not the wealthiest Kingdoms in western Europe. It has lots of rich merchants, and close ties with the even richer merchants of Genoa, Milan, and Florence.

Incidentally, the Union worked out great, especially for Castile. The peace from Ferdinand's Aragonese army and stabilizing 40 year reign allowed population to boom, to the point that a generation later there were a surfeit of young adventurers ready to conquer the New World. Castillan manpower and military experience, plus Aragonese seafaring and monetary connections put the newly united Spain in the drivers seat for profiting off the New World, and made Spain the most powerful nation in Europe for the next 150 years.

Answer 2

Well, this is a somewhat problematic situation. You see, if you want it to be based on real-world royalty and the like... then you are in for a shock.

Let's start with the trouble of royal lineage. To be considered a proper royal (and therefore a suitable partner), you had to be of royal blood--or at the very least of noble blood. That meant, either you marry your family, or you marry a foreigner.

In fact, in Europe and Tsarist Russia, it was quite common for royalty to marry the cousins, nieces, daughters, or granddaughters of other royals. This is why queens were expected to have so many children in those days--more sons to lead their country, more daughters to bargain off to other countries.

Note that it's far more common for a woman to be offered to another country. Some countries (England for example) would rather a reigning queen than a foreign king (Queen Elizabeth I is a prime example of this, though she'd refused to marry for a host of reasons, some of which were hinted at as being plausible sexual abuse. Check this video for background information on Elizabeth I and Mary, Queen of Scots, and this one for how hereditary diseases spread through royal blood, which also shows how marriage often worked for royalty)

If this isn't enough information, you can always nose around in the BBC documentaries on the subject. There's always more going on behind the scenes, and two main players have always been the church and the politically snobbish. You may also wish to get into coming of age ceremonies of the time, and how this affects your two monarchs. I assure you, though, that a king marrying a queen is all but unheard of (unless I've missed something). They would be looking in the best interest of their kingdom, so unless the queen offers her hand in marriage to her would-be conqueror (Cleopatra to Marc-Anthony of Rome, for example, though I don't believe they'd wed), I don't see them joining quite in the way you imagine.

Trade partners, perhaps. Allies against a common threat, oh yeah. Unifying two kingdoms via marriage... not historically accurate as far as I am aware. Mary, Queen of Scots does offer a sort of halfway between, her son became king of Scotland, and also inherited the crown of England on Elizabeth's death, given she never married and had no heir. Beyond that? Beats me.

Answer 3

If you're looking for something a little less radical than political union, you could have a go at an intermediary economic entity, roughly based on the East India Company. This company would be (very) large, able to hire its own security forces to keep the peace. Majority investment (and control) would be by B, with the goal of the company the development of A. With a large enough presence, the company could have a large impact on the functioning of A without overt political control by B.

Of course, this would need very careful political handling by both governments, and a certain amount of enrichment of B would certainly cause resentment in A. A very tricky balance (particularly in the PR field) would be necessary. And preventing the company from getting the bit between it teeth and actually supplanting the government of A would always be a problem. With economic power comes political power, and the temptation on the part of the company's directors would be intense. So you'd need considerable trust on the part of the government of A, while the government of B would need to have strong reasons to keep A healthy and independent.

This would clearly call for some creative writing on your part.

Answer 4

Leaving dynastic issues aside, the only way to have merged taxation is through political union. By definition, only the state may impose taxes. Anything else is a loan or grant from one state to another, e.g., after WWII, the Marshall Plan had the US give loans to rebuild (Western) Europe.

There are also things like the tithe system, in which the Roman Catholic Church collected taxes from officially independent kingdoms, as the successor of the Roman Empire, but without the title or responsibilities thereof. These are more legal fictions rather than anything you could legally repeat (normally).