Map thief Peter Bellwood left a trail of "razored" antique books in museums across Europe.
Peter Bellwood was caught on CCTV in the Copenhagen library
His criminal activities began at the National Library of Wales in Aberystwyth in early 2000, months after his release from prison.
But the trail also took the 50-year-old from Colchester, Essex, to Denmark and there the alarm over his map-ripping was first raised via the internet.
At one stage Bellwood was on the UK's top 10 list of wanted criminals.
Now Bellwood has been brought to book for stealing maps which he sold on to collectors, amassing £70,000 from the National Library of Wales.
On Wednesday at Swansea Crown Court he was jailed for four-and-a-half years.
He confessed to stealing 50 maps, although the library maintains 105 were taken.
They included pages from atlases dating from the 17th Century and other rare manuscripts.
The library has admitted security there was not good enough.
"Clearly they (the security measures) weren't 100% successful," said national librarian Andrew Green.
"It's impossible for them to be so, without closing the doors and keeping them closed, and we've a responsibility to allow people to see what's in the library."
But it was the Danish Royal Library in Copenhagen, where Bellwood is still wanted for numerous alleged thefts, which first uncovered his illicit activities.
Jesper Jorgensen, the library's security chief, issued a worldwide alert by posting his photos on the institution's website. That led to the library finding out that Bellwood had already been convicted in the UK.
Danish authorities want to extradite Bellwood over alleged thefts
Bellwood had been caught red-handed on the library's CCTV system in the act of razoring rare prints, despite disarming suspicion by handing in a 500 kroner note, worth £46, to staff, claiming to have found it "lying around".
"Bellwood's earlier activities were first revealed by the Royal Library of Denmark," said Jorgensen.
"His activities in Wales first came to light as a result of the alarm sent out by this library."
But the discovery came too late to apprehend the thief. He had apparently already left the library, never to return, having allegedly got away with maps from a series of old atlases and rare 16th Century Dutch travel books.
The haul there was valued at £100,000. None of the stolen items has been recovered and Danish authorities
have begun extradition proceedings against Bellwood.
The identification of Bellwood on the internet led to other libraries checking their own collections to see whether he had visited.
The Royal Library of Stockholm in Sweden ran checks and discovered that Bellwood and another UK national were both frequent visitors from August 2000 to January 2001.
It found 40 maps from at least six atlases were missing.
The Royal Library in the Netherlands also discovered 55 maps had been removed from atlases there - although in that case Bellwood was not the thief.
When the former landscape gardener was finally arrested in July, his trail of map-ripping across Europe finally ended.
But it is feared much of what he stole could be lost forever. With strong black market demand for rare maps and prints, the chance of recovery any of the maps seems marginal.