A Human male member of House Palpatine was the grandfather of the human aristocrat Cosinga Palpatine. Around 135 BBY, the Gungan species and a mercenary army of Naboo people were engaged in a war on the Mid Rim planet Naboo, with House Tapalo and House Veruna providing the most funding to the mercenary army. When Palpatine's grandfather learned that the true reason for the war was access to Naboo's plasma, he challenged Tapalo to a duel that took place at House Palpatine's ancestral home, Convergence on Naboo. Tapalo killed him with his blade during their duel.
Around 65 BBY, at Convergence, Cosinga Palpatine told of the Gungan–Naboo War and his grandfather's fate to Magister Hego Damask, who was, in reality, the Sith Lord Darth Plagueis, in an attempt to demonstrate why Tapalo's son, Bon Tapalo, should not be elected as the Monarch of Naboo. In response, Plagueis stated he considered Palpatine's grandfather's actions to be romantic and human.
Cosinga Palpatine's grandfather was mentioned in James Luceno's 2012 novel Darth Plagueis.
Cosinga Palpatine's grandfather was mentioned in James Luceno's 2012 novel Darth Plagueis.