I didn't do justice to him on Tuesday: it seems he was one of 6 conspirators in the "Babington Plot", which freed Elizabeth I's hand to execute Mary Queen of Scots.
His poem was one of 3 he wrote home to his wife from prison. Wikipedia makes great play on his Renaissance use of Antithesis and Paradox -- so, perhaps not much scope for jihadist feeling.
He and the other 5 were disembowelled live in St Giles Fields, which caused such a stir that the next 'traitors' were hung and drawn first. They were all convicted of colluding with Philip of Spain