The benefits of a monarch who produced a lot of offspring, especially sons, for example King Rama IV, once his son took the throne as King Rama V, having a lot of brothers and step brothers, he had helps assisting his duty in various fields which was necessary for developing his Siam a modern country up to those western countries.
Seen in the photo is King Rama V with his step brother, His Holiness the Supreme Patriarch at Wat Bowornniwet in 1905.
(Colored version of a B&W photo)