Today in Postal History

This registered postal stationery envelope was sent from Curepipe.
Curepipe is in the middle of this island east of Madagascar in the Indian Ocean.

Mauritius became a crown colony after it was ceded to Britain in 1814.
It became independent within the Commonwealth on March 12, 1968.
Foreign mail transit was erratic until 1864* when service was established
by Messageries Impériales brought a regular service to Europe via Aden.
Messageries Impériales was operated by the French Government.

In accord with the sender's request Enrégistreé, the cover was marked with a bold R.
An oval registration stamp was overwritten with a registry number.
The backflap was sealed with wax.

I'm not sure what the sender intended by the script No. 1 at the lower left front.

There are two Curepipe CDS.
The alignment is such that you can imagine that they were struck
in sequence by a right-handed clerk as he turned the cover over.
The octagonal La Reunion a Marseilles marking* was added by Messageries Impériales.

There are two subsequent numberings of the cover - Reg 1109 and 673.
I don't know where these were applied although aboard
the mailship, France, and Belgium are possibilities.

The cover's destination was Gand where its arrival was marked by a receiver.
I can't interpret the date of the CDS, however.

Gand, now Gent or Ghent,is almost equidistant from Ostende, Antwerp, and Brussels.

The 30c indicia is taken from the Coat of Arms issue of 1895.

*Thanks to David Benson for correcting the Messageries Impériales marking.
Thanks, too, to David Detrich for catching my typo on the year date.