i answered a more specific one about leonardo alone here, but here are some of my general favourite things about the important figures of the italian renaissance

• on her deathbed, caterina sforza said to a monk: “se io potessi scrivere tutto, farei stupire il mondo" (if i could write everything, i would shock the world) which i think just makes her the second coolest person in the entirety of italian history
  
• speaking of the coolest person in italian history, da vinci took so long to finish the last supper that when the prior complained, leonardo said that the reason it was taking so long was because he couldn’t find a face that was so filled with evil that would fit judas, but if the prior was so desperate to have it finished, leonardo said that he would use him as a model
• lucrezia borgia was said to have a hollow ring that she used for poisoning drinks
• michelangelo hated everyone. he mocked leonardo for his failed statue in milan and had a bitter grudge with raphael ever since raphael looked at one of his paintings before it was released
• leonardo, in turn, wrote bitchy comments about michelangelo in his diaries
• seriously if someone were to make a show about the renaissance artists, it wouldn’t be some high brow drama, it would be something along the lines of mean girls crossed with the office
• leonardo: “omg michelangelo, i love your fresco. what inspired it?” 
  michelangelo: “the bible” 
  leonardo: “vintage, i love it!”
  leonardo [after michelangelo walks away]: “that is the ugliest fucking fresco i have ever seen”
• da vinci himself was really well liked by everyone but he was such a fucking DORK he used to buy caged birds and just to release them and was a chronic procrastinator. he was also gay af and the love of my life
• machiavelli’s ‘the prince’ is the biggest piece of mancrush literature since plato’s symposium
• also they were like, all gay, all the renaissance artists except for raphael who was tragically heterosexual. michelangelo wrote really over the top romantic letters to some dude, and da vinci was arrested for sodomy
• @ historical fiction that tries to make my guys into aggressive womanizers: fuck off
• so if the artists were the sitcom of the renaissance, caterina sforza is the blockbuster politics heavy action film. she literally occupied the vatican on behalf of her husband by riding across the tiber river on horseback while seven months pregnant
• she was honestly so fucking savage when the orsis family threatened to kill her children she ‘exposed her genitals’ and said  “do it, if you want to: hang them even in front of me…here I have what’s needed to make others!” and they were so fucking shocked they didn’t dare touch her children
• i could make a whole post about her, she was so fucking cool i adore her she is incredible
• moving on, this: “the theory is that people were generally not too enthusiastic about the catholic church’s regular massacres of jews and muslims, because the people they were killing looked like jesus.  pope alexander vi then ordered the destruction of all art depicting a semitic jesus and commissioned a number of paintings depicting a caucasian jesus. his son, cardinal cesare borgia, was the model for these paintings.”
• cesare tried to kill lucrezia’s first husband and probably did kill her second. he also apparently came to her wedding dressed as a unicorn, the symbol of purity which is just about the most laughable thing he ever did in his life
• botticelli claimed that the prospect of marriage gave him nightmares

this kinda swayed a lot from being just about the artists, but i hope it was what you were looking for!