So who would know Donald Trump’s movements and involvements best?

Probably his bodyguard of the last two decades, or at least that’s what the House Intelligence Committee believes.

The committee will be calling Trump’s former bodyguard to question him about a trip Trump took to Moscow in 2013, as well as what he knows about the firing of former FBI Director James Comey.

Keith Schiller has been summoned to appear before the House panel on Tuesday, where lawmakers will press him on Trump’s 2013 trip, which is detailed in the infamous, unverified dossier compiled by former MI6 agent Christopher Steele.

The dossier, intended as 2016 campaign opposition research, was initiated by Republicans but eventually taken over by Democrats.

The dossier contained a lot of information that could be considered troubling. Some of it, such as reports of meetings between Trump representatives and Russian officials has been verified. Other portions, like the pee-pee tapes, have not.

The House Intel Committee must feel Schiller, who left Trump’s employ in September, has something of value to share.

It was Schiller who delivered the letter to Comey, informing him that he was out.

It was also Schiller who informed a longtime advance logistics aide and former director of White House advance George Gigicos, that he would never manage another Trump rally, after an August Trump rally in Phoenix. The venue was less than full, and Trump blamed Gigicos.

“The White House is delighted that Mr. Schiller will have an opportunity to shed some light on these scandalous allegations, and we are sure that his testimony will be of great interest to all fair-minded people,” White House lawyer Ty Cobb said in a statement to the Post.

The dossier claims that Kremlin officials have “kompromat,” which means compromising material, against the president.

Schiller left the White House in September, reportedly to take a better paying job. He took a massive pay cut to work with the Trump White House (reportedly from $294,000 annually to $165,000).