This work is dedicated to the British author Jane Porter and her four-volume novel "Thaddeus of Warsaw", written in 1803. Porter's novel is a romance dealing with a fictitious Polish patriot Thaddeus Sobieski, who is in fact modelled on Tadeusz Kościuszko - Poland's national hero. Porter presents the brutal fate of the Polish Commonwealth during the Partitions and the adventures of Thaddeus Sobieski as an immigrant in London. My work tries to shed a new light on the depth of Polish-British cultural links on the basis of Porter's work. The study also shows the 'behind the scenes' of producing "Thaddeus of Warsaw" and Porter's life as well as the magnificent reception of the author and her book 200 years ago in the Isles. Finally, since currently little is known about Porter and her novel in both Poland and Britain, or elsewhere, this book is a tribute to the person whose creation highlighted the Polish cause after Poland had been murdered.