during the Second World War. Joyce's defence team, appointed by the court, argued that, as an American citizen and naturalised German, Joyce could not be convicted of treason against the British Crown. However, the prosecution successfully argued that, since he had lied about his nationality to obtain a British passport and voted in Britain, Joyce did owe allegiance to the king. Thus, Joyce was convicted of treason, and was eventually hanged. After Napoleon fell from power for the first time, Marshal Michel Ney swore allegiance to the restored King Louis XVIII, but when the Emperor escaped from Elba, Ney resumed his Napoleonic allegiance, and commanded the French troops at the Battle of Waterloo. After Napoleon was defeated, dethroned, and exiled for the second time in the summer of 1815, Ney was arrested and tried for treason by the Chamber of Peers. In order to save Ney's life, his lawyer André Dupin argued that as Ney's hometown of Sarrelouis had been annexed by Prussia according to the Treaty of Paris of 1815, Ney was now a Prussian, no longer owing allegiance to the King of France and therefore not liable for treason in a French court. Ney ruined his lawyer's effort by interrupting him and stating: "Je suis Français et je resterai Français!" (I am French and I will remain French!). Having refused that defence, Ney was duly found guilty of treason and executed. Until the late 19th Century, Britain - like various other countries - held to a doctrine of "perpetual allegiance to the sovereign", dating back to feudal times, under which British subjects, owing loyalty to the British Monarch, remained such even if they emigrated to another country and took its citizenship. This became a hotly debated issue in the aftermath of the 1867 Fenian Rising, when Irish-Americans who had gone to Ireland to participate in the uprising and were caught were charged with treason, as the British authorities considered them to be British subjects. This outraged many Irish-Americans, to which the British responded by pointing out that, just like British law, American law also recognized perpetual allegiance. As a result, Congress passed the Expatriation Act of 1868, which granted Americans the right to freely renounce their U.S. citizenship. Britain followed suit with a similar law, and years later, signed a treaty agreeing to treat British subjects who had become U.S. citizens as no longer holding British nationality -