EThere is scarce documentation available for the time that followed. It seems that Eltern was strongly affected by the Thirty Years' War (1618-1648). Until 1622, the area stayed unaffected by any troubles. Soldiers from Mansfeld and afterwards imperial troupes behaved barbarously. "Soldiers from Mansfeld and afterwards imperial troupes destroyed and burnt down houses,..., lands can not be rent out anymore and parcels are ravaged." Not only Haseluenne, but also its surroundings were affected. Farmers were impoverished and houses became derelict. One farmer from Eltern was so poor that his sons did not want to accept the inheritance.
It took a long time until the region recovered from the effects of the Thirty Years' War. Between 1650 and 1661, then-bishop of Osnabrueck Franz Wilhelm von Wartenburg surveyed his diocese about their believe. Primarily, he wanted to receive an overview about the number of communicants and non-communicants in his bishopric in order to evaluate the confessional situation. The result, however, was a nearly complete population register. According to this register, in 1652 Eltern had 44 persons older than 14 years living in twelve families. Approximately 100 years later another register listing the villages' inhabitants was set up. This register stated that there lived 115 inhabitants in Eltern in 1749. Among them were 47 children younger than 14 years of age. There were 19 families: 9 were sole heirs (cultivators) and 10 Heuerleute (landless cottagers). Today's family names already existed in these registers and also in the tax lists of the following centuries. Furthermore, registers show that Eltern had a pure agricultural structure which only changed today. Regarding the school's chronicle from 1882, Eltern's first schoolhouse was already built in 1732. It was located at the place where the Heuermann (landless cottager) of the sole heir Cordes lived. Between 1830 and 1840 another school was constructed only 100 meters farther. Later, also this building became obsolete and was knocked down. On July 6, 1930 a new schoolhouse was opened which was used for education until its closing on September 9, 1971. Changes in the school system led to the abolishment of the small schools in the villages. Eltern's children now went to schools in Haseluenne. The former schoolhouse was adapted and serves until today as a kindergarten.
It is also important to mention that in the same century several residents of Eltern quested for happiness in foreign countries. They emigrated to Hungary, but returned later. At the same time others migrated to the United States. Historians are not sure if emigration took place due to economic or political reasons.
The rule of Napoleon led to the liberalisation of farmers. Making a ransom payment they could receive liberty in 1854. At the same time, the redistribution of jointly used lands led to tedious negotiations.