text: From 1801 , in order to symbolise the union of the Kingdom of Great Britain with the Kingdom of Ireland a new design , which included the St Patrick 's Cross , was adopted for the flag of the United Kingdom of Great Britain and Ireland .
simplified: From 1801 , in order to symbolise the union of the Kingdom of Great Britain with the Kingdom of Ireland , a new design was adopted for the flag of the United Kingdom of Great Britain and Ireland .