Born in 1805, Louis-Martin Porchez first arrived in Guadeloupe with the first bishop, then went to Martinique. When Monsignor Leherpeur died, Louis-Martin was vicar general of the diocese. He became the bishop of Martinique on November 21, 1858. His episcopate was brief; he died on June 12, 1860 and was buried alongside Monsignor Leherpeur.
The coat of arms of Monsignor Porchez [1858-1860], depicted on a stained-glass window in the left side aisle, near the transept, displays:
A square shield,
– chief on a blue field with the Marian monogram
– base on a red field with a coconut tree symbolizing the island, the anchor to mark the arrival by boat and a handshake
An ornament: a crown flanked, on the left and on the right, by the insignia of the bishop: the miter and the crosier
A motto: “In Vinculis Charitatis” [In the bonds of charity]