Slingeneyer was also a politician and was a member of the Belgian Chamber of Representatives for the Independists of Brussels, a coalition of personalities bound by their opposition to the Radicalist liberals.

Here he studied during the day painting under the leading Antwerp Romantic painter Gustaf Wappers while in the evening he took drawing classes.

While still a student he exhibited a big canvas entitled The arrest of Louis, Count of Crécy which was received with critical acclaim.

[6] When a National Fund for the encouragement of historical painting art and sculpture was established by Royal Decree of 25 November 1839, Slingeneyer was quick to sign up for it.

[2] Encouraged by his success he created an even more ambitious and larger composition entitled The sinking of the French battleship Le Vengeur.

[7] When The battle of Lepanto was finally finished and exhibited in 1848, it fell short of expectations in spite of its qualities in terms of composition and execution.

His Episode of St. Bartholomew exhibited in 1849 was considered a revenge for his Battle of Lepanto as the work showed strength and a genuine emotion.

This was regarded as a competitor of the workshop of Brussels' prominent painter François-Joseph Navez who was a major promoter of Classicism in Belgium.

[6] In 1878, Slingeneyer received a government commission of 122,000 Belgian Francs to paint a large canvas called Les Gloires de Belgique (The Glories of Belgium) and a series of twelve decorative panels with historical subjects for the great hall of the Academy Palace in Brussels.

Camoëns hung at the exhibition opposite At dawn of Charles Hermans, a co-founder of the avantgarde Société Libre des Beaux-Arts.

The numerous genre pieces with themes from the folk culture of Italy and North Africa that were inspired by these trips were successful and can still count on the interest of today's collectors.

At the end of his life he still received distinctions such as the Légion d'Honneur of France, and the order of Franz-Joseph of Austria, Charles III of Spain, Ernest of Saxon-Coburg, St. Michael of Bavaria and others.

From 1871 to 1894 he was a member of the Board of Directors of the Royal Museums of Painting and Sculpture, of which from 1889 on he became a vice-chairman together with the Orientalist painter Jean-François Portaels.

With the anti-radicalism as a unifying agent, a coalition of doctrinal liberals, conservatives and opportunists had formed in Brussels around a program of 'less politics, taxes and waste'.

He repeatedly intervened in the acquisition policy of the most important national museums, the organization of the Prix de Rome and numerous other cultural and artistic matters.

Slingeneyer further agitated against avantgarde movements in Belgian art such as the Société Libre des Beaux-Arts founded on 1 March 1868 in Brussels, to which belonged Charles Hermans, Constantin Meunier, Louis Dubois, Félicien Rops, Alfred Verwee and Louis Artan de Saint-Martin belonged.

Rather, he explored subjects that allowed him to create dramatic scenes that combined acts of heroism with tragedy, such as in Le Vengeur, the deaths of the sea captains such as Jacobsen, Claessens, Nelson and Camoëns, the Christian martyr, etc.

Jean-François Portaels and Jean Baptiste van Eycken, both pupils of François-Joseph Navez, helped launch the monumentalist movement in Belgium.

[9] Slingeneyer was a commercially astute artist who was able to adapt to the changing taste of the moneyed class of Belgium, which initially was liberal and partly favorable to the French Revolution and also in awe of the major maritime nations of the time.

This explains the subjects from French, Dutch, Portuguese and English maritime history to which Slingeneyer returned repeatedly early in his career.

It is in this context that Slingeneyer painted his series of works of portraits and scenes of Flemish medieval heroes such a Nicolaas Zannekin, Jacob van Artevelde, Jan Breydel, Frans Anneessens, the Battle of Roosebeke.

Further he created countless genre pieces with themes from the folk culture of Italy and North Africa, which are about the only works of Slingeneyer that can still count on the interest of today's collectors.