A further testament to this devotion included Hasan-Jalal's commissioning of the Gandzasar Monastery. Construction of the monastery began in 1216 and lasted until 1238. On July 22, 1240, amid great celebration during Vardavar celebrations and in the presence of nearly 700 priests including Nerses, the Catholicos of Albania, the church was consecrated. The monastery went on to become the residence and sepulcher of the family as well as the house of the catholicos; beginning in the 15th century, the family also monopolized control over the seat of Catholicos itself, which would from thereon in pass down from uncle to nephew. Hasan-Jalal's son John VII is considered to be the first to have established this practice when he became the Catholicos whereas his nephew, also named John, became the second.