[1] He was the third son of Count Gerlach V of Isenburg-Limburg from his second marriage (fourth altogether).
His eldest brother, Gerlach VI of Isenburg-Limburg, had died in the Black Death without male heirs in 1365, and his next oldest brother Hermann had died the same year.
Gerlach V had pledged the Lordship of Limburg an der Lahn to the Archbishopric of Trier between 1344 and 1346.
[2] After John's death without heirs in 1406, the House of Isenburg-Limburg was extinct.
He married Hildegard (died 1419) of Saarwerden (a former countship centered at present-day Sarre-Union, France).