Probably for the most part, but I'm pretty sure he added some of that leadership quality and way of being to the part due to him being Patrick. There's also probably some improv here and there. Pity about his kids though. Hope they had a better relationship in the later years.
He did have a very varied life story, but I'm sharing what I did because it's what he expressed about his entire life, especially in the most recent years.
A character he acted did.
Patrick Stewart on his deathbed referred being estranged from his children from always putting work before his kids in his own words.