Former President George W. Bush on Friday unveiled more than two dozen portraits he painted of world leaders, including Russian President Vladimir Putin, former British Prime Minister Tony Blair, and his father, former President George H.W. Bush.

Mr. Bush gave NBC’s “Today” a first look of the portraits in an interview with his daughter, contributing correspondent Jenna Bush Hager.

His passion—which he said was inspired by Winston Churchill—began with an iPad doodling app called Penultimate. Since then, he has hired an art instructor, whom he told: “There’s a Rembrandt trapped in this body. Your job is to unleash it.” He transformed his “man cave” into an art studio, Ms. Hager said.

“He’s very disciplined. He comes up and works every single day, which is why he’s improved and can do portraits of Bob the cat that are so good,” said his wife, Laura Bush.