I’ll admit from the start that I have no direct answer for why leprechauns are associated with shoes. However, if you’ll bear with me for a moment I may be able to provide some small satisfaction on the matter.
When Lug came to the Tuatha de Danaan, he was asked by the gatekeeper what he could provide for the tribe. He responded with a number of professions of which he was a master. Frustratingly, each time he named one he was told that there was already a member of the tribe who was an expert in that field. He only gained entrance when he asked if any member of the tribe had mastered all of the professions he had named. No one had.
It is said that, when the Tuatha de Danaan were sent underground by the Milesians, each group of them was assigned a separate sidh, or hill that served as doorway to the Otherworld. Reasonably, all the groups, cities, or tribes of Tuatha de Danaan would have had the same concerns as they had in the days when Lug had gained entrance. Namely, that there should be one expert for every craft at every sidh.
The leprechauns are generally associated with the Tuatha de Danaan. The leprechauns have the same diminutive size, magical powers, and general association with the sidh as they have. It is also a curiosity that leprechaun is an anglicisized of ‘leipreachán’. Irish ‘ea’ regularly transitions to ‘ei’ and ‘á’ to ‘ó’, giving a folk etymology breaks the first two syllables down to ‘leith’ or half and “bróg” or shoe, in other words someone working on one of a pair of shoes. By that thinking, the leprechaun may be nothing more than a specialist to be found in every tribe. Naturally smiths, carpenters, and other experts would have been welcome, too.
It is curious that, as mentioned in my previous blog, the Fomorians are associated with magic and that, until the Milesians, they were able to hold Ireland from all invasions. Only the Tuatha de Danaan, who intermarried with them, were able to retain control of Ireland. Both facts speak of a hidden knowledge among this original race. The leprechaun may have been the keeper of that knowledge, or one aspect of it that was the most recognizable to the invaders. There is no way to know now. The Fomorians left no records, and their story is too deeply buried in Irish Mythology to learn anything about them.
What can be recovered about them is minimal, and here I would happily invite any thoughts. Up until recently they were thought to wear red. They were normally seen working on a single shoe. They did each own a pot of gold, and if captured they could grant three wishes in exchange for their freedom. Those few things are all that can be reconstructed of them.