It happened in the first century, at the fall of Jerusalem in AD 70. Revelation 11:15 says "The kingdom of the world has become the kingdom of our Lord and of His Christ." That's not future language, it's fulfillment.

Jesus said the kingdom would come before some of His disciples died (Matthew 16:28). Paul said they were already receiving the kingdom (Hebrews 12:28), and Jesus tied the kingdom's arrival to the destruction of the temple (Luke 21:31-32).

The seventh trumpet marked the full transfer of covenant authority from the Old to the New, Christ's kingdom fully established. That trumpet wasn't about global destruction, it was about covenant judgment and kingdom fulfillment, just as Jesus promised.