In the light of the "Brexit" saga and my rather frightening experiences with customs controls I thought about the origins and history of custom controls.

Searching for that history I came on everytime the same work, seemingly "inescapable",
https://books.google.com.ar/books?id=qlD0zOupzOUC&printsec=frontcover&hl=nl&source=gbs_book_other_versions#v=onepage&q&f=true
from
https://mag.wcoomd.org/magazine/wco-news-78/tribute-to-professor-hironori-asakura/

As I understand it there was "something" in Mesopotamia and Egypt, but as I read it, it is more guessing and imagination than real historical checks...The real customs seems to have been started in Classical Greece and its later Hellenistic network as the port of Alexandria. And the start perhaps for good was the Roman "portorium" fully boosted by Julius Caesar.
And about the difference between WTO and WCO:
https://www.wto.org/english/thewto_e/coher_e/wto_wco_e.htm

I have not yet started for the medieval trade and customs, where England and the Duchy of Flanders had that important role, as later Antwerp and Amsterdam in world trade

My own experiences with customs were already from my childhood, when I from hearsay learned about the "butter smuggling" at our Dutch-Belgian border. Wild stories as a steel plate in the heavy American cars behind the driver when he was fired at by the Belgian customers officers when he entered Belgium with his illegal butter. In English I found only this:
https://www.nytimes.com/1962/09/23/archives/smuggled-butter-is-vexing-belgium-dutch-product-continues-to-elude.html

And then much later I had to enter some "test experience plates" from our factory into Germany (perhaps mid of the Seventies). I was with a lorry driver of a Brussels company, which was one of our main "expediteurs".
And yes I found even a German "tinted" (trouble to find in English the figurative word for "tinted"? (tinged?)) history source about customs control from that company I just told about.
https://gerlach-customs.com/news/the-history-of-customs-from-the-beginning-to-the-present/
And yes that Prussian "Deutsches Zollverein", which helped to unify Germany...
And what an amount of red tape I was witness of...just for my three packages of my "test plates"...and time...I was really astonished by it...

And perhaps is "customs" only one way from the "state" (in the beginning the "prince"?) to earn money. 

(And btw where comes that term "customs" from? From the French "coutumes"? And why not "tol", "Zoll" as in Dutch and German. We here in Belgium say "douane" as in French. As from the medieval Latin "toloneum" and christian Latin "teloneum" and the Greek "telonion" and "telos" (tax))

The much bigger income for the state (and before for the "monarch") is taxation in general?

In my childhood with the "nuns" we learned already from our early years on the stories of the "Bible" as Jesus and the "tollenaars".
And those "tollenaars" were put in such a pejorative light that we already from childhood on were prepared (and it seems especially in Belgium) to evade "taxes" and to do business "in the black". In Jersey they call it I think that more polite "tax evasion"?

Yes those "tollenaars" from the "Bible" ("Tax collectors?")
It took me some time to find an equivalent word in English
while even in Dutch it is not a "nowadays word"
http://etymologiebank.ivdnt.org/trefwoord/tol1
":diamonds: tollenaar zn. ‘belastinginner’. Mnl. toelnars ‘tolgaarders’ [1267; VMNW], tolnare ‘id.’ [1268; VMNW], tollenaers ‘id.’ [1397; MNW ongelt]. Ontleend aan middeleeuws Latijn tolonarius ‘tolgaarder’, een variant van Latijn telōnārius, dat afgeleid is van telōnēum of telōnium.
Lit.: W. de Vries (1922), ‘Etymologische aanteekeningen’ in: TNTL 41, 189-206, hier 199"
In German is it "Zollner"

And from the Bible of Julius Caesar's and "Augustus' time (Temp that " ' " is really not easy in English...the Saxon Genitive?) I found now by this artilce that it was perhaps "tax farmer"?

https://www.britannica.com/topic/taxation/Shifting-and-incidence
And yes later on it was many times a source of revolts from the common folks against higher or new taxations as I read especially in France.
Of course the leading privileged ones had made it easy for themselves (they were exempt of tax). The clergy prayed, the nobilty fought for them and "them" worked and payed taxes for the former two "stands".
.
As I read the Britannica article it says it nearly all about the history of tax collection.
If anyone more knowledgeable as any comments on tax collection?... nordmann?...

The difference between "customs" and "toll" is more than just between a romance and Germanic term for the same thing. Originally they had two very distinct meanings and in some sense this distinction is retained today, though admittedly only by those speaking very carefully (legal text writers, for example).

Customs, as the word implies, was derived from a term related to levies imposed on goods at a customary point of sale. In medieval times there was a legal distinction also between private and public sale. A shop or place of business was essentially considered a private establishment within which the sale of any good or service was a private arrangement between private individuals. Markets on the other hand were considered public and also, for many centuries, represented the locations in which by far the greatest volume of goods - and money - changed hands. These were essentially therefore the "customary points of sale" referred to, and also where the levies were imposed.

"Toll", "Zoll" etc, has a much older pedigree - going all the way back to the Greek "telos", which was a word used to describe a tax on anything, and for many centuries this meaning was retained. As opposed to "customs", over which the recipient exchequer exercised very little control over volume and therefore predictable amounts collected, "toll" covered any or all means the exchequer might employ to collect any amount of money it itself determined to be needed. "Tax" and "toll" are therefore much more interchangeable in terms of meaning than "toll" and "customs".

Prior to income tax people encountered these levies through two principal means. If you owned property then you were liable to pay your lords and masters a sum based on the value of that property. For many centuries these levies were described as "tax" or "toll" and the amounts deemed to be due were thoroughly legislated for and advertised by the authorities so that when the knock came on the door (or you went on the appointed day to the tax collector) there was little dispute about the amount involved beyond the complaint that it was exorbitant. At least one could not normally gainsay the method or the sums involved having been meticulously advertised in advance to arrive at a non-negotiable figure - a bit like they still are today.

The other encounter most people had with official levies was when they were on the road, or river, or open sea, especially if also moving goods as well as themselves. Here they encountered tolls levied to use these ports, roads, and of course markets (which is why markets were so strictly licensed by the authorities). Over the years "toll" became more exclusively associated with such commerce, whereas "tax" was left to describe the more static levies. "Toll" also became more associated with the provision of these commercial "customary" points of exchange and infrastructural elements. Bridges and roads were self-evident, ports and markets probably less so, as proofs of where the toll money was going.

The final bit of the evolution of the terms in vernacular speech was therefore when "toll" became so synonymous with infrastructure, and the levy on goods became a much more sophisticated affair than simply an extortion racket run on market day to one that had expanded to rigid controls at a nation's borders, it therefore also became necessary to find a term to distinguish one from the other. The levy paid at "customary places" drifted, along with the practise, to the borders.

All the above of course only explains why the terms have come to acquire semantic differences. It does nothing to explain the evolution of tax collection which, as your research also hints at, covers as complex, myriad, and uniquely diverse degrees of state extortion as human imagination is capable of. And when it comes to extorting funds by the state, human imagination knows no bounds.

I am still trying to figure out, for example, how a value can be added to an item by imposing an extra tax on it, which of course puts up the price often to the point that it can be classed as a luxury item, at which point another tax can be levied on top of everything else just on that basis alone. I have had experienced accountants and public law officials attempt to explain VAT to me, only for them all to realise that when you actually think about it it's simply tax on nothing, or in essence a tax placed on a value that is itself based on a price inflated by a tax so that the correct value has long been obliterated in the calculation and therefore any "value" added is simply "tax" added and the actual value of the original good plays no role whatever - the modern version of the daylight or window tax beloved of late medieval monarchs running out of funds to keep themselves in luxury goods (bet they didn't pay VAT on them though!).

nordmann, thank you very much for explaining to me the semantic difference between "toll" and "customs". And that in a gradual and historic way from where that difference came. I think I now understood it all.

About VAT, as I said to Meles my parents were fish merchants and they had a lot of trouble, when it was started. And it was also at the same time the start of needing a "bookkeeper" (why is it now not "book keeper"? Yes that English language...)
And of course in that time as customs were..."in black"...I explained it recently to Meles or was it to Vizzer?)...

And as with you they explained the VAT (overhere BTW/TVA) to me. Especially I learned about it, when I with all my refurbishings of buildings had the choice to do something myself and had to pay a 21% VAT on all materials and goods that I bought to do the work, but I had also the choice to let it do from an "entrepreneur" and pay on the whole, services and goods, but then with a special regulation for buildings older than 50 years,  then only a VAT of 6% on the whole. If there was a lot of material and not so much work, it was more interesting to pay only 6% on the whole to the entrepreneur, instead of the 21% on the materials and then I had at the end still to do the work myself...

As I understood it from the explanations on the VAT: in each intermediate step in the process of an "end" product, the entrepreneur of that step has to pay for instance 6% on the overhere called: "turnover tax". That means 6% on the added value (the difference between his purchase and sale)
For instance a tin of "carrots": first the farmer, then the collector, then the super market and in between all the costs of the distribution of the carrots and all the red tape by the employees in the distribution sector...

To "short circuit?" to "shunt?" all this, perhaps just take your car and drive to a farmer from nearby and buy the carrots and pay "official" for the "6%" or in black to gain even that "6%" for you and the farmer and "processing yourself" the carrots, instead of those several steps with at each step "6%" on the added value...
I spoke with Americans about that practice and those are certainly not the same as those bloody Belgians heard from their talkings, but of course it could have been also some fake (Farisee) sermons of them...

Kind regards, Paul.