In 1298, King Adolf von Nassau founded a Poor Clare monastery just outside Wiesbaden. His wife Imagina von Isenburg-Limburg as well as his mother Adelheid were close to the mendicant orders of the Poor Clares and Franciscans that emerged in the 13th century with their striving for piety, contemplation and a simple life: Adolf's mother was a benefactor of the Imperial Poor Clare Monastery in Mainz, founded in 1277, where she also found her final resting place. Imagina, born Countess of Limburg, had met the Poor Clares in her homeland and, as she wrote in a document, had been passionate about their ideals of piety since her youth.

King Adolf was therefore familiar with the work of the Poor Clares when he founded Klarenthal. The possibility of accommodating unmarried or widowed female members of the household spoke in favor of choosing a nunnery - here, noble ladies could find an appropriate place to be cared for. Nevertheless, the foundation of the convent was also linked to power politics, as can be seen from its furnishings. In order to be able to exist at all, it was necessary to provide the Poor Clares with income in kind and monetary interest as well as a base of land. King Adolf bequeathed three farms in Biebrich and Mosbach to his foundation. By donating these lands to his monastery, he removed them from the danger of alienation by the archbishops of Mainz and other competing powers.

However, the foundation of Klarenthal primarily had a spiritual dimension: it was the burial place of the Walram line of the House of Nassau, albeit only for around 70 years, and a place of prayer for the dynasty. The name and date of death of the relatives were recorded in so-called death books or necrologies; the memory of the deceased, his memoria, was preserved by reading out these entries. King Adolf was laid to rest in Speyer Cathedral, but his wife Imagina, his sisters and ten other countesses and counts of Nassau were buried in Klarenthal.

Only a few structural remains of the buildings of what was long known as the "new" monastery, in contrast to the Clarissan monastery in Mainz, have been preserved. The monastery church fell into disrepair in the 17th century. It was located in the northern area of the cloistered precinct or closed it off to the north. It had a lay choir to the east, where the main altar was located, and another choir to the west, referred to in the sources as the "lower or virgins' choir", which could be accessed from the monastery buildings and was used by the nuns for choral prayer. The building was flanked by a probably hexagonal west tower. The main entrance to the church was probably also located in the west. An almost square inner courtyard enclosed by a cloister housed the cemetery: during excavations in the 1960s, numerous human bones were discovered here. The other cloister buildings adjoined this - the infirmary, refectory, convent room, kitchen, wash house and bathing room. Other buildings or parts of buildings were the dormitory, a large dormitory which probably served as accommodation for the lay nuns, the granary, bakehouse, wine press house, two barns, the confessor's house, a servants' quarters and 28 nuns' cells, as well as a mill in the wider area which was first mentioned in 1317. It was not until 1940 that the so-called abbess's house, a Gothic building at its core, was demolished, the eastern part of which served as the abbess's residence, while the western part housed the hospital or infirmary. The entire complex was surrounded by a wall with four gates leading into it.

In addition to the actual nuns, who had taken their vows and were subject to the strict rules of the order, which included vows of poverty and silence, there were also some lay sisters who belonged to the servants of the convent and worked as maidservants; they came from the surrounding villages. The lay brothers or converts also came from the surrounding area; they worked outside the cloistered area on the monastery's own farm or in viticulture. The spiritual care of the nuns was provided by members of the Franciscan order. The abbesses were not allowed to say mass or hear confession, which the nuns had to make twelve times a year; they needed a confessor and a chaplain who traveled from Mainz. The monastery estate was managed by a court master.

If you consider the wealth of funerary monuments in the Klarenthal Poor Clares monastery, despite the simplicity of the furnishings required by the rules of the order, you realize the magnitude of the loss of this place of worship. At the beginning of the 17th century, there were still around 20 tombs. The oldest was probably that of Queen Imagina, whose year of death is not known; it was located in the middle of the choir in front of the main altar, but was later moved to the cloister. The tomb of Mechthild, daughter of King Adolf, was located opposite in the "lower choir" in front of the altar there. Two elaborate double tombs, perhaps decorated with so-called pleurants, stood on the long walls of the nave of the church in partially painted vaulted niches. They were the resting places of Count Gerlach and his wife Agnes as well as their son Adolf and his wife Margarethe from the 14th century. Some of these gravestones were moved to the Mauritiuskirche(Mauritiuskirche, old) in Wiesbaden after the monastery church fell into disrepair, where some of them were removed at the beginning of the 19th century or perished in the church fire in 1850. Fortunately, the painter Heinrich Dors has preserved the inscriptions and illustrations.

The frescoes, which were also handed down by Heinrich Dors, were remarkable. One wall in the lower choir shows the founder's picture: King Adolf and his wife holding up a church, incidentally the only depiction of this building. The Virgin Mary, to whom the church was dedicated, and her son are enthroned above the founders. The royal couple were surrounded by their eight children. The portrait, executed in grisaille technique, probably dates from the first half of the 14th century. Another wall painting above the tomb of Count Adolf I of Nassau-Idstein and his wife Margarethe seems to have existed in all its colorful glory at the beginning of the 17th century. The crucified Jesus was depicted against a blue, star-studded sky with his mother Mary and the disciple John on either side. At the foot of the cross knelt the princes and their sixteen named children in an attitude of worship. Two girls, Margarethe and Anne, were depicted in clerical garb, presumably as Poor Clares, and two sons in episcopal regalia.

In the second half of the 15th century, the monastery began to decline. The great Mainz Abbey Feud from 1461 to 63 was a major contributing factor. The abbesses managed their affairs unwisely and monastic discipline loosened. The monastery was plundered during the Schmalkaldic War in 1546. When the Margrave of Brandenburg-Kulmbach marauded through the Middle Rhine region with his troops in 1552, the convent virgins had to seek shelter behind Wiesbaden's walls, in the local castle to be precise. The following year, the plague struck and the Reformation took hold in the region. 1560 marked the end of the monastery. Soon afterwards, the church began to fall into disrepair.

The House of Counts endeavored to put the administration of the monastery estates on a new footing. In 1607, Count Ludwig von Nassau-Saarbrücken, who had also acquired the Wiesbaden-Idstein part of the land in 1602, set up a hospital in the former monastery building as a care facility for the poor, elderly and sick. A completely different use was envisaged in 1704: At the suggestion of a Frenchman, a manufactory for the production of Venetian mirrors was set up in Klarenthal. However, this "factory" was completely uneconomical. On top of that, a fire broke out in 1723, in which many of the buildings burned down. In the following years, attempts were made to establish paper factories here, but none were successful. The church was demolished, the land and remaining buildings were leased and have been used for agriculture ever since.