It's not that there's no evidence for Robin Hood, it's that there's too much. In court rolls and other government documents, different people at different times were given the nickname "Robin Hood" to signify that they were outlaws, suggesting that there was a legend already. This goes back to 1262. Before that, the evidence waits to be discovered; the court rolls and other documents of that era are very difficult to read, and no-one would think of doing so in a quest for a single name! Although a Robert Hod who was outlawed for non-payment of debt does turn up in the 1226 York Assizes, there is no evidence whatsoever that this is the famous outlaw or that he had any exploits at all apart from skipping town to get out of paying! It seems from a marginal note that his nickname was Hobbe, not Robin, in any case.

The upshot is that a "real" Robin Hood is not actually well-documented, or even documented at all. To quote Jeffrey Singman's 1998 book, "no widely accepted candidate has been found, and it may be questioned whether such a discovery is at all possible."

The stories about Robin's death at Kirklees date to the late 1400s at least--the prioress, who is Robin's cousin, in fact bleeds him to death rather than poisoning him, because she is in cahoots (and in love) with an enemy of Robin's, Roger of Doncaster. This is alluded to in several ballads, including the Geste of Robin Hood.

The grave site at Kirklees cannot be verified, and the stone marker that reportedly used to stand there until the eighteenth century is certainly a fake. The epitaph was based on a poem by Martin Parker written in the seventeenth century, but translated into pseudo-old English. It identified Robin as the Earl of Huntingdon, but the Earldom of Huntingdon was held by the Scottish royal family during the relevant centuries. Thus, unless we are to believe that the King of Scotland (or one of his brothers, depending on the year) was running about as an outlaw in England, it is impossible that Robin was the Earl of Huntingdon, and thus impossible that the epitaph is anything more than a cute piece of fiction.

Geez, we happen to be talking about two of the things I've researched recently: tree-lore and Robin Hood! Sorry to be such a...well, nerd!