Guinness World Records argues that Northern Ireland is a subordinate administration and not a sovereign state. Belgium will now retain the record after it survived without a government for 541 days.
In 2010/11 it took this long to form the Di Rupo administration. During these 541 days PM Yves Leterme led a caretaker administration.
Northern Ireland in the UK has been without a government since January 2017 when Sinn Féin pulled out of the Foster administration.