User blog comment:Nagumo baby/Guide to Castlevania Chronology II/@comment-5234760-20120627201145/@comment-3200351-20120628090241

In case you want to know what the connenction between all games is, the story of the series is essentially about a feud between Dracula and the Belmont family. Dracula was good friends with a knight named Leon Belmon when he was still human. Due to certain circumstances he ended up betraying Leon and became a vampire. As a result, Leon vowed that he and his descendants would hunt down Dracula until he was gone for good. This origin story is told in Lament of Innocence.

Each story from there one is about a descendant of Leon trying to defeat Dracula. But due to Dracula's powers, he is able to be resurrected by his followers. Thus, most games have roughly the same story, just with a different protagonist each time.

Regarding Portrait of Ruin, the protagonists of that game are Jonathan Morris and Charlotte Aulin.