Other literary forms
Unlike his more famous brother Philip and his sister Mary, Sir Robert Sidney was not a prolific writer. Indeed, his career as a poet was probably confined to a few years, possibly as few as two. There are many letters by him in the Sir Robert Sidney papers, but he published no literary work in his lifetime. Likewise, his poetry remained in manuscript, probably at Penshurst, until the early nineteenth century, when it found its way into the Warwick Castle Library. The manuscript was first positively identified by P. J. Croft in 1973 and purchased by the British Library in 1974. It was subsequently printed in a modern-spelling version by Katherine Duncan-Jones, published as The Poems of Robert Sidney in 1984 by Oxford University Press.