As the current crisis involving President Trump and Ukraine’s president unfolded out of the public eye during the first half of this year, one of Trump’s most useful lackeys played a central role: Rudy Giuliani.

As the president’s personal lawyer and bellicose mouthpiece, Giuliani stepped into the gap that opened during “a months-long fight inside the administration that sidelined national security officials and empowered political loyalists,” reports the Washington Post.

While several White House insiders played roles in what one official called a “bloodletting” within the administration, the Post says, “the person who appears to have been more directly involved at nearly every stage of the entanglement with Ukraine is Giuliani.”

Rudy — he did all of this,” one U.S. official told the Post. “This s—show that we’re in — it’s him injecting himself into the process.”

The former New York City mayor — a private lawyer, not a government official — apparently saw Ukraine’s inexperienced new president, Volodymyr Zelensky, as vulnerable to U.S. pressure and “a potential ally on two political fronts: “punishing those Giuliani suspected of playing a role in exposing the Ukraine-related corruption of former Trump campaign chairman Paul Manafort, and delivering political ammunition against [Joe] Biden,” the Post says.

Giuliani’s work, “done with the president’s explicit blessing, involved chasing leads on possible origins of the Mueller investigation. It eventually led to his attempts to dig up dirt on the Biden family,” reports the Daily Beast

As we now know, with release of the transcript of Trump’s phone call to Zelensky on July 25, the conversation that Trump calls “friendly and totally appropriate” was anything but.

Apparently seeking political or personal dirt that would aid his 2020 re-election campaign, Trump pressed Zelensky to order an investigation of the former vice president and his son, Hunter, who had done business in Ukraine.

Trump backed it up by ordering a delay in promised U.S. military aid to the Kiev government, which continues to be threatened in the east by Russia and Russian-backed rebels.

“Several officials traced their initial concerns about the path of U.S.-Ukrainian relations to news reports and interviews granted by Giuliani in which he began to espouse views and concerns that did not appear connected to U.S. priorities or policy,” the Post reports, adding that the respected U.S. ambassador to Ukraine, Marie Yovanovitch, “became a primary Giuliani target.”

It’s a telling element in the Trump administration’s internal feud.

Giuliani targeted Yovanovitch with wild accusations including that she played a secret role in exposing [former Trump campaign manager Paul] Manafort and was part of a conspiracy orchestrated by the liberal financier George Soros,” the Post says.

“She should be part of the investigation as part of the collusion,” Giuliani said in a recent interview with the newspaper, adding that “she is now working for Soros.”

Yovanovitch was subsequently ordered back to Washington before her term was up, and Giuliani pounced.

Shortly after her ouster, Giuliani sought to create an unofficial diplomatic role for himself; he said he would travel to Ukraine to push for investigations that would ‘be very, very helpful to my client, and may turn out to be helpful to my government’” according to both the New York Times and the Post.

Sharp criticism of his clearly expressed intent forced Giuliani to cancel that trip, but he later met with one of Zelensky’s senior aides in Madrid and pressed for Ukrainian help against Biden.

There were never any orders given, any formal guidance from the White House to any of the agencies. And the NSC [National Security Council] was scratching their heads: How is this possible?” a U.S. official “familiar with the matter” told the Post.