On Profile this week Mark Coles looks at the life and career of Sharon White.

The daughter of immigrant parents who came to Britain from Jamaica in the 1950s, she rose rapidly through the ranks of the civil service to become one of the most powerful women in Whitehall.

In March 2015, she became chief executive of the communications regulator, Ofcom.

The watchdog is in the news this week for trying to force BT to legally separate from Open Reach which runs the country's broadband network.