When power shifts at the top of some of the world's biggest companies, most people don't notice.
If products perform, services work and store shelves are full, then who sits in the boardroom doesn't make headlines. But when it comes to Samsung, the family dynasty behind it is so complicated – and the company so crucial to the South Korean economy – that it's front-page news.
And so it was in 2017 when the Samsung heir-in-waiting, Lee Jae-yong - who is also known as JY Lee - was jailed for his part in a corruption scandal that also brought down the country's president.
The 57-year-old is the grandson of Samsung's founder. Geoffrey Cain, author of the book Samsung Rising, described him as "one of the most powerful people in the history of technology".
But in 2015, with his father – Samsung's chairman – in hospital following a heart attack, Lee's succession was not secure.
