Complex sentence: Niall, Coirpre, Maine, and Fiachu, from which came the Southern Uí Néill, are credited with conquering lands from the "Laigen" (Leinster), roughly equating to the present-day counties of Longford and Westmeath (containing Tara).
Split into simpler sentences: Niall, Coirpre, Maine, and Fiachu, from which came the Southern Uí Néill, are credited with conquering lands from the "Laigen" (Leinster). These lands roughly equated to the present-day counties of Longford and Westmeath (containing Tara).