Grotius College has set up a mobility project for teacher in the Bilingual stream of the school. The course was in Cardiff, organised by International Study Programmes (ISP). Reason to initiate the course was that the level of competence within the bilingual team could meet with some improvement, specifically in the field of cooperation with the English department en the role of the English language within the lessons of other subjects. During the project the following goals were adressed: 1. Improvement of the C.L.I.L (Content and language integrated learning) skills in the lessons of all bilingual teachers 2. Improve the quality of education in the bilingual stream at Grotius College, and emphasise the international dimension of it. 3. Make sure the improvement of quality in the lessons is shared with the team members that could not go on the course. The project was carried out by Grotius College and ISP, the latter organising the course. Although originally the plan was to send 20 teachers on the course, 14 actually participated. This because of the amount of time the participants need to spend on the course and the high demands of the board of Grotius College, as in which teachers were allowed to participate. The course we did was the following: "Collegiality Across Content and Language Integrated Learning: Practical methodology on content and language integrated learning for teachers of English in secondary & vocational schools and for C.L.I.L teachers who teach subjects Bilingually". The course took place from 7-15 november 2015 in Cardiff. The following activities were carried out: 1. Workshops on CLIL methodology, with emphasise on collegiality and cooperation between subject teachers and English teachers. 2. Visit to St. Fagans National History Museum en St. Fagans Castle. 3. Visit to a secondary school in the vicinity of Cardiff, to speak with Welsh colleagues and learn about education in Wales. The project lead to the following results for the teachers: -The participating teachers have greatly impoved their skills in CLIL. They are now much more capable of implementing language into their subject lessons. This ofcourse improves our bilingual stream all together. -The lessons of our teachers are now more effective, because the students learn more than before. The teachers noticed quite soon after the course that it had become easier to implement language into their lessons. -The teachers are now more capable of explaining cultural differences to the students because of their own experiences in Wales. The project lead to the following results for the students: -The quality of the bilingual lessons the students attend has improved much, so the results are better. The students profit a lot from the course their teachers took. -Intercultural awareness of the students has increased due to the new ways of teaching. They know more about other (Anglo-) cultures and how that could effect their education and future career. The project lead tot the following results on organisational level: -Due to the project varies meetings were set up to discuss and exchange ideas about CLIL and how to implement this in the lessons. -Internationalisation has taken an important spot on the agenda for the future of Grotius College. It is now a bigger and more important part of the schools policy. There is still room for improvement but it’s position is now clear.