He was born in Plaški,[2] a village in Karlovac County, Croatia, into a family originating from Austrian Italy, as the Donadinis had moved to Korčula from Vicenza or Mantua sometime around 1750.
As a result of his father's heavy drinking, the family went bankrupt and his parents divorced, leaving Ulderiko and his siblings (six sisters and one brother) in dire straits.
After a couple of months in the military hospital, where he faked mental distraction to avoid service, Donadini was finally proclaimed ineligible for the army, enabling him to lead an extravagant life style over the following years.
Donadini is best remembered as the editor of the short-lived literary journal Kokot (1916–1918), in which he introduced expressionist and Avant-garde ideas into Croatian literature.
[4] Due to his constant criticism of stable and preferred social institutions that enable the functioning of civil society, Donadini is also considered to be the successor to Janko Polić Kamov.