To happen.
To fall upon; fall all over; overtake
To happen to.
Case; instance; circumstance; event; incident; accident.
To act as a flagship for.
The most important one out of a related group.
The ship occupied by the fleet's commander (usually an admiral); it denotes this by flying his flag.
The ship regarded as most important out of a group, e.g. a nation's navy or company's fleet.