In 2005, Rupert Murdoch famously sided with his right-hand man, former Fox News chairman and now disgraced businessman, Roger Ailes, over his son, Lachlan, in a television dispute.He chose proven loyalty over blood ties.

Perhaps it’s a lesson Lachlan never forgot. Because after a decades-long succession battle over his family’s media empire, he came out as the victor in September, over three of his siblings. And with the help of a little known power-broker who has become the closest thing to being an honorary Murdoch.

Today, media writer Calum Jaspan on Siobhan McKenna, the unlikely ally from a humble background in Canberra who manages Lachlan’s conflicts, in order to help him retain power. And the impact this has on his professional - and familial - relationships.