Since an underwhelming first spell with the club that saw him spend more time on loan than actually in the Chelsea blue, the Belgian hitman has become quite the well travelled player.
It was not always a smooth road home either, as Lukaku often came under heavy fire for some of his performances, particularly in Manchester red.
However, his move to Inter was the real catalyst as Lukaku became one of the most feared strikers on the continent, driving the Italian side to domestic glory.
Now, it seems that the plan was always to return to Chelsea, where Lukaku would have felt he had a pile of unfinished business.
The early signs suggest that it is going to be an incredibly fruitful partnership, with Lukaku scoring within the first half of his return to action for the Blues against Arsenal.
It really does look as though the sky is the limit for Lukaku at Chelsea, and it would be no surprise to see both individual and team awards start raining down at Stamford Bridge during this spell.
You can only admire Lukaku for his determination in the face of fierce criticism to prove that he truly is one of the best in the world.
The ruthless streak he has already tapped into at Chelsea is ominous to say the least and, with the Champions League title already neatly nestling on the mantlepiece, expect more silverware to follow.
So, as the Lukaku hype train continues to gather speed, we thought we would jump right on in with a quiz about the brilliant striker.
Now is your chance to prove you are a true Lukaku fan boy by answering 20 questions about the life and times of the bona-fide superstar.