The Lancastrian red rose was introduced after the victory of Henry Tudor at the Battle of Bosworth in 1485 .
The Yorkist faction used the symbol of the white rose from early in the conflict , but the Lancastrian red rose was apparently introduced only after the victory of Henry Tudor at the Battle of Bosworth , when it was combined with the Yorkist white rose to form the Tudor rose , which symbolised the union of the two houses ; the origins of the Rose as a cognizance itself stem from Edward I 's use of `` a golden rose stalked proper . ''
Wars of the Roses