How long did Britain remain separate from the Roman Empire after Julius Caesar's unsuccessful invasion in 55 BC?

Julius Caesar's initial foray into Britain in 55 BC was more of a reconnaissance mission than a full-scale invasion. He landed with his legions, but faced fierce resistance and quickly returned to Gaul (modern-day France). It wasn't until nearly a century later, in 43 AD, that the Romans, under Emperor Claudius, launched a successful invasion and began their long-term occupation of Britain. So, while Caesar's initial visit was significant, it didn't lead to immediate Roman rule. The intervening period saw continued trade and contact between Britain and the Roman world, but Britain remained independent. Therefore, the correct answer is 100 years, representing the approximate time gap between Caesar's initial visit and the sustained Roman conquest under Claudius. It's easy to misremember the exact dates, but thinking of it as roughly a century helps to solidify the timeline.