FR 6974 then BA 8066 at Barcelona
Rome → Barcelona → London Gatwick
Timetable, Barcelona time
22:25FR 6974 from Rome at the gate
13:25BA 8066 to London Gatwick leaves the gate
15 h apart on the timetable, overnight
BA 8066 leaves 15 h after FR 6974 arrives on the timetable: more than half a day, so not a connection we count.