Casino Kingdom is 100% legal and has licences from the Malta Gambling Authority (MGA) in Malta.
It is part of the Casino Rewards Group which has a slew of Micorgaming casinos including the quintessential Pure Microgaming casino, Quatro Casino (700 free spins & 100% Bonus), Golden Tiger Casino ( €/$1500 welcome package), Zodiac Casino (Deposit €/$1 and get 80 Chances to be a Millionaire).