Some years after it was first mooted, a new sort of Gaelic dictionary started to be planned in the Scottish Universities in the 1990s, utilising computer-based techniques to generate a corpus of words for analysis, and applying lexicographical principles exemplified in such historical dictionaries as OED and DOST. This project took shape in the early 2000s as Faclair na Gàidhlig. As the concept became clearer, so did the scale of the task; and so, simultaneously, did the conviction that FnaG had a central role to play in fulfilling educational needs and national aspirations for the future well-being of Gaelic. It is worth recalling at this point how FnaG evolved, and highlighting the key circumstances and critical factors which enabled it to progress to the point we have reached today. It is likewise important to recall several particular challenges which Scottish Gaelic presents to the lexicographer. Some of these are purely linguistic; others are rooted in the historical and social circumstances of Gaelic speakers, but with significant effects on the consistency of the data available to lexicographers. Many lessons have been learned from the experiences of lexicographers working with other languages, while some questions have required us to customise or extemporise. Many decisions have been taken, though answers to some thorny questions are still emerging. As we now move towards the completion of the foundational phase of FnaG it is important to look ahead, to envisage and prepare for the different sorts of challenge which will confront the project as a new generation of lexicographers goes to work on the historical dictionary of Scottish Gaelic.