the earliest know name of the shannon–erne waterway was the river gráinne (sruth gráinne in irish). sruhagh townland lies on the north shore of that part of the river which connects ballymagauran and derrycassan lakes and it derives its name from that situation. the earliest surviving mention of the townland name is in a poem (poem 2, verse 29) composed about 1291 a.d. in the book of magauran which gives the name as "sruth gráinne"-