"Castle Of Dromore", in Gaelic "Cáislean Droma Mhor", also known as "October Winds" is an Irish song.
There are at least four castles named Dromore Castle in the counties of Down, Kerry, Limerick and Tyrone. Dromore Castle, in County Tyrone is the most likely subject of the song. Clan Owen in the second verse refers to the descendants of Eoghan, anglicised to Owen who once possessed the counties Tyrone, or Tir Eoghan, and Derry and parts of County Donegal.
The words of the song were written by Sir Harold Boulton to a traditional Irish tune. The Irish Gaelic words are a translation into Irish of Boulton's lyric, made by Douglas Hyde. The Irish lyrics are from Songs of the Four Nations, edited by Harold Boulton (1892). Harold Boulton also wrote the lyrics of "The Skye Boat Song" and "All Through the Night" using the Welsh melody "Ar Hyd Y Nos".
The melody was printed in O'Neill's Music of Ireland: 1850 Melodies (1903).
I learned this from the recordings of Gordon Bok, Ann Muir and Ed Trickett and the Clancy Brothers. I was never too interested in the words but the melody is beautiful.