From the start of the French Revolution into the early 19th century , the revolutionary blue-white-red tricolour was used throughout England , Wales and Ireland in defiance of the royal establishment . During the 1816 Spa Fields riots , a green , white and red horizontal flag appeared for the first time , soon followed by a red , white and green horizontal version allegedly in use during the 1817 Pentrich rising and the 1819 Peterloo Massacre . The latter is now associated with Hungary but then it became known as the British Republican Flag . It may have been inspired by the French revolutionary tricolour , but this is unclear . It was however often accompanied by slogans consisting of three words such as " Fraternity – Liberty – Humanity " ( a clear reference to '' Liberté , égalité , fraternité '' ) , and adopted by the Chartist movement in the 1830s
Peterloo Massacre
Peterloo Massacre
Republicanism in the United Kingdom