“It is ‘consequent upon’ and not ‘consequent to.
Consequent upon his resignation, there was a cabinet reshuffle.
He resigned consequent upon his disagreement with the boss.

'Subsequent’ is followed by ‘to.’
Subsequent to his resignation, there was a cabinet reshuffle.
Subsequent to his arrival, there was a commotion at the airport.

So please remember that it is ‘consequent upon’ and ‘subsequent to.’”

Meaning of ‘French Leave.’
“When you leave your place of work without permission, your boss may ask you why you had taken ‘French leave.’ The expression is from the eighteenth century French custom of leaving a social function without saying goodbye to the host or hostess. The idea was that one should leave the party quietly without disturbing others. Now ‘French leave’ means leave taken without permission.
He took French leave to attend the cricket match.”