of Leiden as Geertgen's birthplace is roughly traceable to Johann Kessler's dissertation of 1930. He died, probably still in his twenties, around the year 1495, in Haarlem, where he was buried in the commandry. Modern scholars have attempted to calculate the artist's death date with the information from The Painting-Book (Middle Dutch: Het Schilder-boeck) by Karel van Mander, published in 1604. The reconstruction of Geertgen's active dates has recently been done by Kemperdick and Sander in 2007 stating: (Geertgen's) two paintings in Vienna indicate a self-assured artist; of the works attributed to Geertgen, they are certainly among the most mature and independent. If the artist was really only twenty-eight when he died, then the altarpiece began at about thirteen years of age and lasted four to six years, so that Geertgen can have ended his training at the earliest by the age of about eighteen. Should he have gone to work for one or two years as a journeyman, then the age at which he began to live by his art correspondingly rises. Accordingly, Geertgen worked a maximum of ten years independently. ...If one now dates the altarpiece for the Knights of St John to around 1490, then Geertgen must, roughly speaking, have been born around 1462/1467 – after the inscription on Matham's engraving in Leiden – and would have begun his apprenticeship around 1475/80. In the 14th century Haarlem was a major city. It was the second largest city in historical Holland after Dordrecht and before Delft, Leiden, Amsterdam, Gouda and Rotterdam. In 1429 the city gained the right to collect tolls, including ships passing the city on the Spaarne river. At the end of the Middle Ages Haarlem was a flourishing city with a large textile industry, shipyards and beer breweries. Around 1428 the city was put under siege by the army of Jacqueline, Countess of Hainaut. Haarlem had taken sides with the Cods in the Hook and Cod wars, and thus against Jacoba of Bavaria. The entire Haarlemmerhout wood was burnt down by the enemy. In 1469 the commandry of St. John in Haarlem was promoted to a special status that fell directly under the grand Prior of Germany. Before that it was a subordinate commandry of the Balij of Utrecht, which had 12 commandries reporting to it. The commandry of St. John became quite wealthy from donations by the local families Berkenrode, Assendelft, van Brederode, Tetrode,