The series are definitely unrecommandable for children or young teens. Spartacus shows a lot of disturbing scenes; some are very bloody, gory, and violent in every way. You will see things such as guts (flying, at times), severed limbs, men eating maggots, crushed faces, murders (bloody and very visual), exc..
Sex also is not left aside; in every episode you have your share of explicit nudity and penetration. You cannot go a second without seeing boobs. They are everywhere. You will have your fair share of full frontal male and female nudity, sometimes there will be close ups. There is also moaning, prostitution, male to male penetration, allusions to rape (explicit), frequent mention of sexual related cuss words (cock, cunt, clit, fuck, whore, ..). Cursing is also prominent, people curse almost non stop.
Watching this show without the violent or the sexual scenes makes it loose a bit of it's flavour. It's plot line being centred around theses two subjects, it would be impossible to watch it without any of theses scenes. Besides, there is hardly any scene at all without any of theses two components.
I would only recommend this to mature teens only, for children it would be incomprehensible and would not be able to be savoured (just look at the young children reviews). As to say, this is definitely NOT for children!!!