Lord Tuath was a wealthy noble of the Triune Empire. One of the most powerful nobles of the Empire, he was both respected and honoured for both his domestic and war time exploits. What none had realised, however, was the source of his vast wealth. Though by right of his position and lands, he would in any case have been rich; however, he had, over the years, systematically been supplementing this wealth by fraudulent tax evasion and embezzling from the royal treasury. As Lord Chancellor of the Empire, his opportunities for embezzling were unparalleled, and he was intelligent enough to keep his takings within limits.
In the end, however, even the most successful of scoundrels eventually get found. The Emperor’s security services discovered his wrong-doings, but here was faced with a dilemna. To confront Tuath could have provoked civil war (so powerful was Tuath), and would certainly have struck a great blow to the confidence of the populace in the rulership of the Empire. The Emperor though, was a proud man, and could not stand to see such a traitor go unpunished, and thus decided to assasinate Tuath (though Tuath was honoured, no-one gets as powerful as he was without making a few enemies, and assassination was an accepted political ploy in the Empire at that time).
A band of assassins was duly hired, and successfully entered the city residence of Tuath. Amongst the assassins, was the elven mage Celoniel, then a young man, fresh to adventure. The assassins achieved their task: in ironic justice, Tuath was killed in his study, his dead body slumping over the desk at which he had been completing his fraudulent tax returns. The young mage Celoniel, for reasons unknown, picked up the tax documents - perhaps thinking (wrongly) that they might prove to be of use.
Over the decades, Celoniel continued his career, rising in fame and prowess until he was one of the most powerful mages in the Empire. Through all this time he kept Tuath’s tax documents with him. No-one knows why he did so; some have speculated that he kept them to remind him of his youth and humble beginnings, others have suggested they were a reminder to him of the ultimate mortality of us all, no matter how powerful. Perhaps the most likely explanation is that he simply forgot he had them. Whatever the reason, when, nearly two centuries later, Celoniel - by now a legendary hero, recognised as the pre-eminent mage of the last 500 years - died, the tax documents were found in his position. His possessions were divided amongst his family, and the tax documents ended up in the possession of his nephew, a merchant of Linnarson, who prospered and grew wealthy.
Since then, the documents have passed through many hands, passed on as a keepsake and souvenir: after all, how many things does the average person have that they can say were once owned by a legendary hero? A joking rumour has grown up about the documents, claiming that they may bring the owner wealth; however, none believe it because, although a few of the owner’s have been lucky, the majority have not.
In the two centuries that they were carried by Celoniel, being in the constant presence of so much magical energy meant the tax documents managed to pick up a few magical properties. As this magic was never purposefully added to the documents but just gradually accumulated, it is very hard (almost impossible) for detect magic/identify spells to find out what the documents do (if anything). All that such spells would do (should anyone even think of trying) is reveal that there is a slightly stronger magical field over the documents.
If read once a year, Lord Tuath’s Documents will grant the owner luck in monetary affairs (suggested an extra 15% of money from all things other than picking up loot). This is manifested very subtly; for example, when bargaining, a person would just happen to often strike very good bargains; a merchant would "luckily" buy just the right commodities to make a killing; etc. The person should usually not even be aware of it (though might well think - "Hey, I’ve had a good year this year!"; after all, 15% more than usual is well within the normal fluctuations of chance.