Attracted in his youth to the ferment of revolutionary ideas and driven by a rebellious temperament, Hennequin had an early career that can only be described as troubled. After training at the School of Drawing in Lyon under Donatien Nonotte and Eberhard Cogell, in late 1780 he enrolled at the atelier David had just opened in Paris; however, he was expelled the following year in the wake of a theft of paint for which he was denounced by his fellow student Wicar. He spent the years 1784–1789 in Rome, where he was pursued by the Papal police for his Masonic activities, a situation aggravated by his association with the subversive Count Cagliostro. Taking refuge in Lyon, he played an active part in the French Revolution on the Jacobin side, but had to flee the White Terror after the events of 9 Thermidor and the fall of Robespierre. On his return to Paris in 1796 he was condemned to life imprisonment for his part in the attempted insurrection at the Grenelle army camp, the final episode in the "Conspiracy of the Equals" and its intended overthrow of the Convention, but was released in February 1797. In 1799 he achieved a succès d'estime – more political than critical – at the Salon with his monumental allegory Dix août (Tenth of August), a celebration of the fall of the monarchy; financed by the neo-Jacobin government the work won a first prize from the French Institute. It was destroyed in 1820, but fragments can be found in the museums in Angers, Caen, Le Mans and Rouen. The critics reacted more favourably to his Remorse of Orestes at the Salon in 1800, a sweepingly energetic example of Classical romanticism showing Orestes pursued by the Furies after the murder of Clytemnestra (Paris, Musée du Louvre). Hennequin, though, lacked the wherewithal to compete with the Empire's leading painters and their virtuosity in the celebratory style required by the regime. Heavily in debt, he left France for Italy – with a stopover in Lyon – late in 1806 and finally found refuge in Holland, where Louis Bonaparte tried to find commissions for him. The floods that struck the city of Gorcum in January 1809 supposedly led the aldermen of Amsterdam to commission a painting of the event from him, but the project never bore fruit; the same year saw Hennequin move to Belgium, where his art provided a meagre living until he finally settled in Tournai in 1821.
When times are difficult, commissions in short supply and painters struggling to find outlets for their ideas, the portrait is always a reliable fallback option; all the history painters resorted to it during the French Revolution and Hennequin did so throughout his roving existence. However, the fact that he presented his portraits in exhibitions shows that he regarded them not as mere potboilers, but as worthwhile demonstrations of his talent. Indeed, they display painterly virtues – finesse of execution, psychological acuity and real skill in imitating nature – that are lacking in his history paintings. Moreover, his capacity to establish an intimate relationship with his subjects outstripped that of many of his contemporaries. A new addition to the oeuvre, the Portrait of a Bearded Man possesses all these qualities, while also standing out for its costume: this is the only known portrait by Hennequin showing its model in the antique mode. The beard – at odds with the fashion of the time – and the deeply meditative air of the face hark back to the iconography of the philosopher of old.