Seamus Heaney was Northern Irish, he died in 2013.
This poem was published in 1966 at the start of ‘The Troubles’ in Northern Ireland: a period of deep unrest and violence between those who wanted to remain part of the UK and those who wanted to become part of Ireland.
The first eight letters of the title spell ‘Stormont’: this is the name of Northern Ireland’s parliament.
The poem might be a metaphor for the political storm that was building in the country at the time.