British historian and biographer Andrew Roberts admitted there were plenty, perhaps a plethora of Winston Churchill biographies when he decided four years ago to start his “Churchill: Walking With Destiny” — 1,009 by his count.

Roberts had written four books on the 20th-century British leader and his times, the first going back some 30 years, and he had reviewed perhaps 100 others. So why write biography No. 1,010?

Because, simply put, he found more to say.

“Over the last four years, there’s been a cornucopia of new material,” he said by phone from a recent book tour stop in Amarillo.

Queen Elizabeth II granted him unprecedented access to the papers of her father, King George VI, who met with Prime Minister Churchill weekly during the war years. Roberts also found material in the diaries of Churchill’s daughter, Mary Soames, and the Soviet ambassador to England; transcripts of meetings of the War Cabinet; and boxes of letters and papers acquired by the Churchill Archives at the University of Cambridge’s Churchill College.

The new sources, in fact, forced his hand to do something sooner rather than later.

“It was always going to be my big book. … But I couldn’t have waited another 10 years and written it then,” Roberts said. “Someone else would have beaten me to the new material.”

Roberts, 56, will talk about his findings on Churchill, one of the towering figures of British statesmanship in the 20th century, in Waco on Wednesday night, in “An Evening With Winston Churchill” at 7:30 p.m. at McLennan Community College’s Conference Center.