Debora van der Plas was a works owner and ship owner as well as being one of the major iron exporters in Sweden in the mid-1600s.

Debora van der Plas was born in 1616 in Dordrecht in the southwestern Netherlands. She was the youngest in a group of siblings of whom two older sisters and one brother reached adulthood. She came to Sweden in connection with her father Laurens van der Plas’ appointment to the Swedish court as court painter in 1618. When the family moved to Sweden, Debora van der Plas was only a few years old. Her father also became involved in the iron industry in Sweden, in which he and his son-in-law Lucas Hidding were engaged as the tenants of Axbergshammar wrought iron works in the southern Swedish province of Närke. Lucas Hidding was the husband of Debora van der Plas’ eldest sister Sara.

When Debora van der Plas was 13 years of age, her father died. When she was 28, in 1644, she married Jan van Ruyff from Amsterdam, in Stockholm. Her husband had come to Sweden on the assignment of the Schuylenburch brothers in Amsterdam to buy works businesses on their account. Jan van Ruyff had already purchased the Axbergshammar wrought iron works from Lucas Hidding in 1642. Jan van Ruyff ran the works after that for seven years as the Schuylenburch brothers’ foreman, after which he bought it on his own account. In 1658, Debora van der Plas’ husband died. In the death registry he was called “The Hollander Rifwen”. He was buried in St James’s Church in Stockholm in his brother-in-law Lucas Hidding’s grave. As his widow, Debora van der Plas took over the wrought iron works, which she was to run for 14 years. At Axbergshammar there were four hammers in 1653, with an annual production of about 449 tons of wrought iron. The mine manager, Knut Larsson, wrote in 1673 that “Johan van Ruyff’s widow” had 4 ½ hammers at Axbergshammar and one hammer at the Lunda works.

Debora van der Plas was thrown headlong into the enterprise. Shortly after her husband’s death, the purchase of the Axbergshammar works went through with the necessary authorisations and the same year she was granted permission to build a flour mill in Axberg parish. Business correspondence and legal documents show clearly that she took an active part in the enterprise. Apart from the running of the works enterprise, she was also busy in an international arena with regular business contacts abroad, and she also had good knowledge of the economic conditions in the European market. This is shown for example in her business correspondence for many years with the English firm Marescoe-Joye in London. They were the commission agents of Debora van der Plas’ exported iron products. In these letters she discussed prices and qualities, insurance matters, payments via bankers in Amsterdam, the choice of suitable ships and the range of products. The place of dispatch shows that she was working in Stockholm as well as Axbergshammar. In the letters, it is apparent that Debora van der Plas always had fine goods to offer and that one important export product was so-called “voyage iron”, which was desirable as a method of payment in the African slave trade. This type of wrought iron was more difficult to manufacture, and was only offered by a few Swedish suppliers, among them Debora van der Plas. Among the purchasers of this iron from Närke were the English slave trade companies. Her counterpart in the London firm was firstly Charles Marescoe, and later on his widow Leonora Marescoe.

Debora van der Plas was also one of the more important ship owners in Stockholm. As such, she carried on legal suits against the citizens of Arboga on a few occasions in the 1660s. She complained in 1665 to the Swedish National Board of Trade, since she considered that the Arboga citizens, who owned the privilege of ship transports to Stockholm, could not manage to meet her transport needs. She therefore demanded to meet these needs by using her own ships for the transports. Otherwise she would risk damages from the English buyers waiting in Stockholm for deliveries of wrought iron. She got her own way at the Swedish National Board of Trade who agreed with her arguments and gave her the right to use her own ships whenever she needed, despite the privileges. Five years later, the citizens of Arboga were once again told off for allowing large amounts of Debora van der Plas’ iron to lie waiting in Arboga during the spring and summer, after having refused to let her use her own ships.

Debora van der Plas and her husband belonged to the ten foremost iron exporters in Stockholm during the 1650s. After her husband’s death, she continued the business at that high level. At the beginning of the 1660s she was one of the few women iron exporters, and during the years 1662—1664 she by far the greatest. Of about 150 iron exporters during those years, the number of women varied between four and six, and all were widows. Debora van der Plas exported between about 303—390 tons of wrought iron per year, which put her in the tenth to twentieth place among all exporters during that period. No other woman exported nearly as much. Other goods exported by her were lighter forms of wrought iron and anchor iron. The only woman who came anywhere near Debora van der Plas’ capacity was Countess Ebba Brahe, Jakob de la Gardie’s widow and mother to Magnus Gabriel de la Gardie. Debora van der Plas had greater export capacity for wrought iron compared with her husband’s time. Her capacity at the beginning of the 1660s was considerably above the previous decade’s average. In her closest family circle were several persons who were active in the works business, trade and export.

Debora van der Plas handled legal disputes with success. They might be disputes with other works owners about the rights to produce wrought iron or the purchase of wood and coal. In 1664, she did not pay her taxes for her hammers since she was not in agreement with the Swedish Board of Mines about the taxation system.

In English surviving documents, Debora van der Plas is named by her own name in correspondence as well as accounts. In the Swedish material on the other hand she is often called “Jan van Ruyff’s widow”, without her own name being used. The English documents often use her husband’s surname for her too, as in “Debora van Ruyff”. It probably had to do with wanting to refer to the trademark. The designation VR (van Ruyff) was namely Axbergshammar’s iron stamp and way of marking their products, and this remained the case until well into the 1800s.

After 14 successful years of management, when Debora van der Plas was 56 years of age, she was struck by ill health and was no longer able to run the business. Her daughter Gertrud’s husband Henrik Cletcher, an immigrant merchant from the Haag in the Netherlands, took over the management of Axbergshammar works and other properties. He took care of everything during the remaining years of her life. He described her condition as follows: “is she this year 1672 on account of illness, by means of a suddenly occurring stroke, so totally overcome in her speech, powers, and limbs that she therefore cannot for other than death be considered”. Her daughter Gertrud seems to have been her only child, and Axbergshammar works followed the female line, as they had in at least five instances during the 1600s and the beginning of the 1700s.

Debora van der Plas died in the spring of 1680, at 64 years of age, at her home at Axbergshammar works.