AMSTERDAM.- A man sprayed a chemical over one of the most renowned paintings in Amsterdam's Rijksmuseum Sunday, damaging its varnish, a museum spokesman said. The man was spotted at about 5.30pm on Sunday as he sprayed a chemical substance at the 'Celebration of the peace of Munster' (1648) by Bartholomeus van der Helst. The painting is one of the main attractions at the museum.

The painting is included in the exhibition dedicated to the most important Works of art from the museum´s collection from the XVII century. Experts believe that only the varnish may have suffered damage.

"I saw some kind of vapor coming from the painting and then the man with a bottle in his hand”, one of the guards said. The suspect had been followed by the museum´s security days ago since they had seen him as suspicious but yesterday he introduced himself without them knowing, hiding himself amid tourists. Museum workers immediately attempted to clean the painting and said that an evaluation of the damages would be made.

Bartholomeus van der Helst was a Dutch portrait painter, born in Haarlem, who trained in Amsterdam and settled there before 1636. His early work is influenced by Nicolaes Eliasz Pickenoy, a little known local artist and possibly his teacher. Rembrandt, who was at this time the leading artist in Amsterdam, was also influential. Van der Helst’s mature portraiture was vivid and flattered his sitters, and was possibly more appealing than the pensive and sombre portraits by Rembrandt. Young artists, including Rembrandt’s own pupils Bol and Flinck, were drawn to van der Helst’s novel manner. Following the death of his wife Saskia in 1642 and the critical reception of ‘The Night Watch’, Rembrandt moved to religious subjects and this gave van der Helst the benefit of an unchallenged position as a portraitist of the Republic’s ruling class. Private portraits of Captain Bicker and his family demonstrate his compositional and modelling skills, his fluent brushwork and exquisite rendering of draperies. His reputation lay chiefly with group portraits. His portrait of ‘Captain Bicker’s Company’ (1639–43) painted for the Musketeers’ Hall was followed in 1648 by an even more prestigious commission from the civic guard, ‘The Celebration of the Peace of Münster’ (both Rijksmuseum, Amsterdam). The latter work was considered a masterpiece and established van der Helst’s lasting fame. In 1781 Reynolds praised it higher than Rembrandt’s ‘The Night Watch’.

The painting features twenty-five militiamen. In the Late Middle Ages the first militia units were formed. The various companies were named after the weapons they bore: the longbowmen, the crossbowmen and the arquebusiers, named after the 16th-century weapon, the arquebus or 'klover'. Civic guard units were deployed to quell riots and were called up in war. They also patrolled the city. Militiamen supplied their own equipment and uniforms, so they usually came from the wealthier classes. It was customary for companies to commission artists to paint their portraits. In the prosperous 17th century numerous civic guard portraits were painted. The men are sitting relaxing around a table laden with delicious food and filled wine glasses. On the right two officers are congratulating each other. One is holding a silver drinking horn bearing the figure of St. George. These are crossbowmen, members of the Guild. A guild is a society of persons united by a particular aim or occupation. Guilds were first formed in the Middle Ages. Some guilds were founded as charities, others were societies of merchants, craftsmen, artists and militias. Craftsmen would have been unable to practice their profession without being a member of the guild. Members were bound by a code of quality and price, but could also obtain assistance from the guild. An extensive apprenticeship system developed. Only a fully qualified master could become a member of the guild. Each guild had its patron saint: the patron of the painte´s guild was St Luke. of St George. The blue banner bearing the personification of the city reveal these to be Amsterdam militiamen. The painting is dated 1648, which indicates the reason for the celebration: the Treaty of Munster. The militiamen are celebrating the end of the Eighty Year War. Bartholomeus van der Helst painted this canvas after 1648. He probably spent one or two years working on it, painting the portraits of all the guardsmen, individually. This would explain why the men hardly look at each other.