On Transformers Source
Transformers first started out as Japanese toys way back in 1970s and 1980s as Diaclone with no storyline but just displays for promotion
After Hasbro bought the licence rights from Diacone in 1984, they collaborated with Sunbow to create the first ever animated TV series featuring robots as main characters
The very first animated feature length movie came about in 1986 after TV seasons 1 and 2 concluded and marked the transition between first and second generation Transformers.
After US producers dropped out after just Season 3 trilogy, the Japanese took over and created their own style in storytelling with old and new characters.