As for Bin Talal, he and the president go back at least to the 1990s.
Between 1991 and 1995, Bin Talal came to the rescue of Trump, whose real estate empire was in financial trouble. Bin Talal purchased a yacht from the New York real estate mogul and was part of a group that helped take the city's floundering Plaza Hotel off Trump's hands.
But things have not been amicable between the two billionaires of late.
In 2015, Bin Talal bashed Trump for his rhetoric during the presidential campaign, and even called for him to drop out.
"You are a disgrace not only to the GOP but to all America," he said in a Twitter post. "Withdraw from the U.S presidential race as you will never win."
Trump responded: "Dopey Prince @Alwaleed_Talal wants to control our U.S. politicians with daddy's money. Can't do it when I get elected. #Trump2016"