Eggert was a wealthy skipper and merchant in Haderslev, Denmark. The town of Haderslev’s archive was lost in the Great Fire of 1627, so there is very little to study from the old archives.
A tax record for Stockfleth, 13.12 in 1607 shows a tax of 8 shillings Lubecker (Money from Lübeck was often used for his Eiendom property in Haderslev as well as another property in the same city in which he lived. The estates were in the neighbourhood of the monastery, in that time probably a better street but now it is only a small alley.
It's believed he was a Lieutenant Colonel in Holstein but this has until now not been proven and seems somewhat doubtful. Besides Eggert Stockfleth have a person of the same genus name around 1607 lived in Haderslev, as in Easter P. AW Knudsen and J. Rehm kautionerer for a loan of 100 Lubeck Mark at Kommunitetet in Haderslev for Heinrich Stockfleth.
At the beginning of the 17th Century there was a large number of people emigrating to Norway from Haderslev and from Jutland, especially when the 30 years war broke out in the Jutland Peninsula. The immigrants settled in Christiania (Oslo) and especially in Bragernæs by 1627. Most of the Garman, Stockfleth and Mecklenburg families that emigrated to Norway from Haderslev, occupied leading positions in Drammen including Eggert Stockfleth, who records show living there in 1629. He was probably familiar with Drammen due to his shipping business as the local customs accounts show Danish goods of flour, malt, bacon, grains were received, 27th June 1622, from Eggert Stockfleth of Haderslev.