The coat-of-arms is that of Delfau de Pontalba impaling that of Almonester y Roxas, for Baron Joseph Xavier Célestin Delfau de Pontalba (1754 – 1878) and his wife Micaela Leonarda Antonia Almonester y Roxas (1795 – 1874).

Joseph Xavier Célestin Delfau de Pontalba was born in New Orleans, the son of Baron Joseph Xavier Delfau de Pontalba (1754 – 1834), the first Louisiana born Baron de Pontalba, and Jeanne Françoise Louise le Breton des Chapelles (1765 – 1839). At age four, Célestin moved to France with his mother to care for her aunt, the widow of the former governor of the Louisiana Territory. They were joined by the baron in 1797, and moved into the newly purchased Mont-l'Évêque in northern France. It was here that Célestin grew up, before returning to New Orleans in 1811 for an arranged marriage with Micaela Leonarda Antonia Almonester y Roxas (1795 – 1874), his cousin. Born in New Orleans, Micaela was the daughter of Spanish builder and philanthropist Don Andrés Almonester y Rojas (1725 – 1798) and Louise de la Ronde (b. 1772). Don Andrés was a member of a noble Andalusian family, and had moved to Louisiana in 1769, where he funded the building of St. Louis Cathedral and other important buildings surrounding the main square of New Orleans. Michaela inherited this property, along with her father’s wealth, at his death when she was three. Upon her marriage to Célestin, Michaela, along with her mother, moved to France to live at Mont-l'Évêque.

Once at Mont-l'Évêque, it became apparent that the arranged marriage between Célestin and Michaela was done largely to give Célestin’s father Baron Joseph Xavier immediate access to Michaela’s property and wealth. As he also controlled all aspects of Célestin’s life, Baron Xavier pressured Michaela and her mother to sign over more and more of her fortune, going so far at one point as to forbidding Michaela from seeing her mother until he gave him half her property in New Orleans. Though Louisiana continued to follow the Code Napoléon which stated that a Michaela’s properties were her separate assets, after 1815 France largely removed those laws, meaning that, though they could not get divorced, should Michaela leave Célestin he could take possession of her property. To this end, Baron Xavier went to great lengths to make her life miserable in an attempt to drive her from the family. In about 1830, Michaela left Mont-l’Evêque with her three sons, who fled the boarding school they had been placed in, and stayed in Paris for the next three years as Célestin, and his father, seized the property her mother had left her in France upon her death. In 1834 Michaela returned to speak with Célestin, and while the details of their discussion are unknown, the following morning Baron Xavier cornered her in a bedroom and shot her four times at point-blank range, firing off her left breast and two fingers, but not killing her. As he was out of ammunition, the Baron now 80 years old retreated in despair and took his own life.

Though in recovery for years following this confrontation, Michaela eventually gained control of her property, and built the Hôtel Pontalba on Rue St. Honoré, now the U.S. Embassy residence in Paris, in 1840, before returning to New Orleans in 1849 leaving Célestin behind in France. There, Michaela hired Samuel Stewart to build thirty-two row houses on her property surrounding Jackson Square. Known as the Pontalba buildings, these Greek Revival structures with thin columns and elaborate wrought-iron balconies and decorative elements are still iconic symbols of central New Orleans today. Michaela left New Orleans in 1851 and returned to Paris where she was reunited with Célestin, caring for him in his old age until her death in 1874. Following his death four years later, the two here buried together at Mont-l’Evêque.