When did the manga start?

Answer 1

Before actual manga, there were Japanese painters who drew images in a sequential form, which were mostly whimsical and humorous (there were also paintings depicting Horror, erotic, etc).

At the beginning of the 20th century, when Japan was opened up to the west, American and European comics started coming in. From there on Japanese artists, influenced by western comics, began creating their own. Most were political, or were some sort of social commentary. It was also used for Propaganda during WWII. Manga continued to grow and is now what it is today.