Conversation so far:
Did Leonardo da Vinci have a family?
Leonardo appears to have had no close relationships with women except for his friendship with Cecilia Gallerani and the two Este sisters, Beatrice and Isabella.
Tell me about his personal life.?
inform Leonardo's brothers of his death, described Leonardo's feelings for his pupils as both loving and passionate.
Who were his pupils?
intimate relationships were perhaps with his pupils Salai and Melzi.
Melzi.
Was he close to his pupils?
Leonardo's most intimate relationships.
Was he close with anyone else?
Leonardo's brothers.
What was his personality like?
his extraordinary powers of invention, his "outstanding physical beauty", "infinite grace", "great strength and generosity.
Did  he have friends?
Leonardo had many friends who are now renowned either in their fields or for their historical significance.

Question: Who were some of his closest friends?
Self-contained rewrite: Who were some of Leonardo da Vinci's closest friends?