Several assassination attempts were made on James, notably the Main Plot and Bye Plots of 1603, and most famously, on 5 November 1605, the Gunpowder Plot, by a group of Catholic conspirators, led by Robert Catesby, which caused more antipathy in England towards Catholicism.
Der var adskillige forsøg på at snigmyrde James, heriblandt Main Plot og Bye Plot i 1603, og det nok mest berømte den 5. november 1605, krudtsammensværgelsen, der blev udført af en gruppe katolske sammensvorne ledet af Sir Robert Catesby, der skabte mere antipati overfor katolicisme i England.