It was built by Colonel Erhard Reichsfreiherr von Ehrentreuter of Hofrieth (1596-1664), commander of the Dutch garrison in Emden, between the years 1642 and 1650. He named the castle after his wife Eva, Baroness Ungnad, of Bohemia, whom he had married in 1631. Colonel von Ehrentreuter had been enfeoffed with Loga and the neighbouring village of Logabirum by Count Ulrich II of East Frisia to pay off his considerable gambling debts.
Marie von Ehrentreuter (1633-1702), the youngest daughter of the colonel, married Gustav Wilhelm Freiherr von Wedel (1641-1717) who came from Königsberg. The later field marshal of the Danish King Christian became the new lord of Evenburg and also the Governor of Oldenburg Land. In 1684, having amassed a considerable fortune, he bought the Jarlsberg near Oslo in Norway as well. From that time onwards, the von Wedels were given the title of Count.