"Siúil a Rúin" is a tradtional Irish song, sung from the point of view of a woman lamenting a lover who has embarked on a military career, and indicating her willingness to support him. The song has English language verses and an Irish language chorus, a style known as macaronic.
The title translates to "go, my love" (or variants): siúil is an imperative, literally translating to "walk!", a rúin is the vocative of rún, a term of endearment.
The history of the song is unclear. It was suggested that it refers to the "Wild Geese" of the Glorious Revolution. If it does, however, the original version has probably been lost: All versions of the song have Modern English lyrics, and not a scrap of either Irish or Early Modern English verses survives. It is not uncommon that Irish songs were translated into English, with their chorus surviving in Irish, or being transformed into nonsense words (see Caleno custure me), but in most of these cases, traces of the Irish version survive. It was also observed that the reference to the spinning wheel the girl wants to sell is more suggestive of the 19th than of the 17th century, and it is possible that the song was composed in the 1800s with the conscious intention of styling it after older songs.
Johnny Has Gone for a Soldier is a well known American variant dating to the Revolutionary War, sharing a common melody and similar lyrics.