Mike and Karen Pence have been married for 33 years.

They met in 1983, and ultimately became evangelical Christians together.

They exercise and pray together — and the vice president forgoes eating alone with women other than his wife.

Visit BusinessInsider.com for more stories.

There's a quiet but powerful force at work in the White House.

Her name is Karen Pence.

The second lady's influence often goes unnoticed amid the noisy exits and vicious power struggles that characterize the Trump White House.

But she is in fact the closest adviser to her husband, US Vice President Mike Pence — President Donald Trump's second-in-command.

Karen has sometimes been a focus in some recent controversies, like the couple's expensive decision to walk out of a NFL game over flag protests, and more recently, defending the vice president's decision not to wear a protective face covering when visiting COVID-19 patients at the Mayo Clinic.

The Washington Post once reported that Karen has asserted that she never attempts to sway policy. But her 33-year marriage to the former Indiana governor has been a major influence on him throughout his political career. Karen — whom Mike refers to as "Mother," according to the Rolling Stone's extensive profile in 2017 — is a major player behind the scenes.

Here's a look inside the marriage of Mike and Karen Pence.