Can I start the Skolian Empire Saga with Radiant Seas?

I recently bought the book by Catherine Asaro. The cover looked Hella interesting and fun, so I decided to give it a buy. It has pretty decent reviews on Goodreads and it's a long dedicated series, plus the writer is a physicist which is a HUGE turn on for my reading brain.

The thing is, I didn't know that it was the 4th book in the series when I got it, and I don't have the previous books and can't afford them at the moment.

Is there anyone here who has read the series? If so, do you think the book stands on it's own? I'm prepared to buy the following books too, but I really wanna know if the first 3 books are 100% necessary to read first.