If you thought the famine was something, it came on the heels of a frost that killed more than one third of the population a century before. See http://www.independent.ie/national-news/our-cold-snap-was-nothing-compared-to-th e-great-irish-frost-of-1740-2478360.html

Hmm! the numbers quoted don't amount to a third, more like a fifth - maybe the Irish Independent's calculators are calibrated to a non-decimal base?

Díogha gach síon an sioc (ach bhuaigh an síorbháisteach air)

Numeracy and literacy have suffered here, clearly....

1541 was another bad year, it seems:

http://www.ucc.ie/celt/online/G100005E.html

M1541.0

AOIS CRIOST, 1541. Aois Criost, mile, cúic céd, cethracha, a h-aon.
M1541.1

Doinenn dermhair, sioc, & snechta a t-tús na bliadhna-so co ná ro léicc ar ná treabhadh iar c-coir do dhénamh i n-Erinn.

M1541.0

THE AGE OF CHRIST, 1541. The Age of Christ, one thousand five hundred forty-one.
M1541.1

There was much severe weather, frost, and snow, the beginning of this year, which prevented tillage and ploughing from being properly done in Ireland.