Complex sentence: Due to its dramatic appearance, the Friesian has become popular in the film industry although the historical accuracy of dramatizations using Friesians is dubious given the breed as it is known today only came into being within the last 400 to 600 years.
Split into simpler sentences: Due to its flashy appearance, the Friesian has become popular in the film industry. Though Friesians are of dramatic appearance, sometimes their use in dramatizations of actual historical events is of dubious accuracy, given the breed as it is known today only came into being within the last 400 to 600 years.