[citation needed] She is known as the founder of the Lichtenthal Abbey, a Cistercian nunnery that has operated without interruption since 1245.
She was the daughter of Henry V, Count Palatine of the Rhine, who was also duke of Brunswick, and his wife Agnes of Hohenstaufen.
She and her husband are known as patrons of the monasteries in Maulbronn, Tennenbach, Herrenalb, Selz, Salem and Backnang Abbey.
In 1245, Irmengard founded Lichtenthal Abbey in Lichtental (now part of Baden-Baden, where later the Margraves of Baden would be buried.
The brothers Herman and Rudolf, gave their mother Irmengard, who had begun the construction of a Cistercian monastery at Beuren, near Baden, for the salvation of her late husband, the Margrave of Baden, and for the reduction of her sins, but had insufficient means, the Jus patronatus of the churches in Ettlingen and Baden, the tithes in Iffezheim (deciman, que nobis cedit aqud Vffinshein), the villages of Winden and Beuren with all lands belonging thereto, two manors in Oos and one in Eberstein, and twelve pounds of coins from Strasbourg from their interest in SelzIn this case, the brothers gave away more than they owned, because they had earlier enfeoffed Louis of Liebenzell with two parts of the tithes.