While both were highly respected artists, their rivalry stemmed from several factors:
* Competition for commissions: Both artists were highly sought after, and Bramante felt Leonardo received more prestigious commissions, like the famous "Last Supper."
* Artistic style: Leonardo's innovative techniques and mastery of perspective challenged Bramante's more traditional approach.
* Personality: Leonardo's enigmatic and aloof nature contrasted with Bramante's ambitious and assertive personality, creating a dynamic of envy and frustration.
However, it's important to note that the exact extent and nature of Bramante's jealousy are debated among historians, as there is no direct evidence of his feelings towards Leonardo.