The Erasmus+ KA131 Mobility project of Democritus University of Thrace encompassed Student Mobility for studies and traineeships, as well as Staff Mobility for teaching and training, spanning a duration of 26 months (1/6/2023 - 31/07/2025). Throughout the project's implementation, the objectives included: a) achieving the University's goals for modernization, internationalization, and extroversion; b) addressing the needs and goals of each participant, whether student or staff; c) ensuring compliance and harmonization with the programme's regulations for quality implementation (in adherence to the binding ECHE principles) and proper funding management (by the Special Account for Research Funds-ELKE); d) implementation of activities in alignment with the 2021-27 horizontal priorities. The project aimed for both quantitative and qualitative goals, such as retaining and enhancing the quality and quantitatively increasing student mobility, particularly outgoing students, for both studies and traineeships, as well as teaching staff for training and teaching. Additionally, the project aimed to increase the number of incoming staff through the 3rd (October 2023), the 4th (May 2024) and the 5th (May 2025) International Week of DUTH. One of the main challenges has been the fact that seven academic Departments have been integrated to Democritus University of Thrace, adding about 85 academic staff, 64 administrative staff and 5.062 students, increasing the number of academic staff by 10%, of administrative staff by 13,8% and of active students by 14,8%. During the transition period of the merging, the uninterrupted continuation of the outgoing and incoming mobility flows has been a challenge for several months, during the negociations and the procedure for the budget transfer from the previous university to DUTH.