She had her revenge, for forthwith soldiers were dispatched by her lordly patron to arrest the offending priest and make him prisoner. But the latter hearing of this in time, made good his escape to the famous glen of Aberlow, where he lived for years a hidden life. It was while thus cashiered and ostracised that he conceived the idea of writing the history of Ireland, from the earliest times to the Norman conquest, afterwards travelling through the country in disguise, with Aberlow as base, to consult the ancient MSS., which were then in the families of the hereditary brehons and in the proximity of the old monasteries. Many documents which existed in 1630, and which he perused, have since disappeared. And his work is thus of great value, as he rewrote and redacted their contents in his own words, like another Herodotus. Duald Mac Firbis, his contemporary, was equally indefatigable in ransacking the past for the benefit of the future. His _magnum opus_ is _The Book of Genealogies_. O’Curry thinks it perhaps the greatest national genealogical compilation in the world. In addition, he compiled the _Chronicon Scotorum_, various glossaries, and, according to himself, a dictionary of the Brehon laws. Almost at the same time that Keating was writing his history in the south of Ireland, the Four Masters were busy with theirs in the north. Michael O’Clery, born at Donegal about 1580, was author of the Leabhar Gabhala, or Book of Invasions, and other important works, but in compiling the famous Annals, the greatest of all, he had the assistance of other three eminent scholars, known as Farfasa O’Mulchonry, Peregrine O’Clery, and Peregrine O’Duigenan. Hence the name “Four Masters,” given by John Colgan of Louvain, himself worthy to rank after them as the author of the _Trias Thaumaturga_, a book which owes its origin to the vast collection of material amassed by Michael O’Clery throughout his busy life. The latter work consists of two enormous Latin quartos, the first containing the lives of Patrick, Brigit, and Columba; the second, those of a number of other distinguished Irish saints. From the middle of the seventeenth century we are carried forward to the beginning of the eighteenth. And the next great name that illuminates the pages of Celtic scholarship is that of a Welshman, Edward Lhuyd. A peculiar interest and distinction attach to the work of this man, inasmuch as he was the earliest pioneer of the modern philological movement, and almost stumbled on the discoveries of Grimm and Rask, which were only reached upwards of a century after his time.