Definition & Meaning of "now then"in English

What does "now then" mean in British slang?

It is used in British English, particularly in Northern England (especially Yorkshire, Lancashire, and Manchester), to say hello in a friendly, informal way, similar to "hey up" or "alright?" People typically say "Now then, mate" or "Now then, how are you?" The term originated in Northern English dialect, possibly as a shortened version of "now then, what's happening?" and remains a strong regional marker of the North of England.