Once called the "Queen of the Danube," Budapest has long been the focal point of the nation and a lively cultural centre.
Budapest's once had a queen
'Once called the "Queen of the Danube," Budapest' - doesn't say whether Budapest actually had a queen or not
( z1 have :ARG0 ( z2 city :name ( z3 name :op "Budapest" ) ) :ARG1 ( z4 queen ) :time ( z5 once ) )