C.O.L.U. Sisters Convent and place of Formation, first was in the farm confiscated from a German citizen Rangwi. The land had been given to the Trappists towards the end of the 19th century. It was probably bush at that time.
Thanks to God that the buildings for starting a convent were already there. In 26 December 1952 the government announced publicly that the Diocese of Tanga owns a piece of land in Rangwi.
In the same place of Rangwi there was a building which was a fruit industry owned by a Germany settler, it was then already given to the diocese. It was fit to be used as one of the convent buildings.
In 1954 was the right time when the Congregation of Our Lady of Usambara (COLU) started under Sr. Willibalda Giesbers CPS the Mother General, helped by Sr. Ambrosis Möllers.
The first group of 7 candidates came to Rangwi ready to start their new life, in 6/12/1953, together with Bishop Eugen Arthurs I/c, Fr. Francis Kennedy I/c, Mr. Hein, Sr. Willibalda Giesbers CPS, and Sr. Ambrosis Möllers. The names of these candidates were; Atanasia, Genovefa, Veronika, Yohana, Theresia, Regina, Gratiana, Eugenia, Sabina, Yohana and Clementina.
At this time Rangwi had only three buildings which were formally the fruits industry. The buildings were not in a good condition since were old. These girls lived in and tried to reconstruct the buildings. They had to work hard, because they were very few and the convent needed a lot of things to be dealt with. Among those buildings, one was the store; this was changed to a chapel.
Bishop Arthurs I/c, Fr. Walter Dick I/c, and Fr. Jack Reed I/c helped very much in daily activities of this convent especially Shamba, animal keeping, building new house and others.
In 8/12/1954 the Mother House of Rangwi was consecrated having 13 candidates who were officially accepted as postulants. In 2/2/1956 the postulants made a step forward to Noviciate. A short time before making their first vow one among them died, this is Sr. Natalia.
In 2/2/1958 it was the appropriate for COLU to have the first 11 girls who made their first vow. It was a good and memorable day to all with good heart. It was also a happy day to Bishop Eugen for he had always dreamed for this day. This first group had; Sr. Ancilla, Sr. M. Magdalena, Sr. Bernadeta, Sr. Francisco, Sr. Theresia, Sr. M. Goreth, Sr. Veneranda, Sr. Jasinta, Sr. Lucia, Sr. Margaretha and Sr. Patricia. Bishop Eugen Arthurs lead all who came Rangwi for that occasion to praise God in the holy mass.
After that, the work of making Rangwi a good place for COLU sisters went on, and on the 9th April 1958 stood another building for Prophesy Sisters. Sisters went on providing services of teaching religion in schools and health services to the health centres. At the same time they went on learning different activities e.g. cooking, gardening, animal keeping, making clothes etc.

Mission in the parishes.

In 7/10/1958 seven sisters were sent to Lushoto Parish for mission activities. Lay people welcomed them happily. This joyful day in Lushoto parish started with the mass. The mass was said by superior general of Rosminian Fathers, who by then was Bishop Eugen Arthus. Also Mother General Sr. Willbalda Giesbers CPS, Sr. Ambrosis Möllers CPS and other sisters from Rangwi attended the mass. The sisters took many activities in the parish like teaching religion in the school, cooking, washing clothes, cleaning houses, garden etc.
In 2/2/1961 the first 11 sisters made the 3 years vow, 9 noviciates made their first vow and 12 postulants entered noviciate. It was really a good day to see a good number of girls giving themselves totally to Jesus and serve His church. Construction of Rangwi Convent still went one and Fr. John O’kane came to join the sisters and help them. It was at this time, they managed to put the generator and supply electricity power to all buildings in the convent including the Grotto of Mary Mother of God. During the night this Grotto was very attractive because of the light. We pray to Mary that this light shines to the heart of all people and be good followers of Christ.
1961 Fr. John O’Kane I/c left Rangwi and Fr. Michael Egan I/c took his position. Pastoral activities grew up, and in the same year for the first time four sisters were sent to Kilole parish for the mission work. These were Sr. Brigittem, Sr. Francisco, Sr. Patricia and Sr. Inviolata. More sisters were needed in different parishes and in 18/11/1962 Sr. Goreth, Sr. Venerenda, Sr. Angelica, Sr. Joseph, Sr. Mayola and Sr. Richarda were sent to St. Anthony Tanga and later two sisters who were the teachers joined them, these were Sr. M. Edith and Sr. Inviolata. In 1963 Sr. Irimgard, Sr. Auxilia, Sr. Scholastica and Sr. Inviolata were sent to Mazinde parish for mission work. As the mission work increased the same time the number of sisters in COLU increased and sent in the parishes. In 1967 Sr. Johanita, Sr. Scholastica, Sr. Elizabeth and Sr. Selina were sent to St. Theresia Parish for mission work.
1969 – 1970 Sr. Inviolata was appointed the headmistress in Chumbageni Primary School Tanga.
In 1960 Sr. Ambrosis Möllers CPS who was assistant Mother General became seriously sick, and was sent to Nairobi for treatment, but her health couldn’t make up, so she was sent to Germany and died in 11 August 1961. Her position was taken by Sr. M. Boniface CPS who arrived at Rangwi in 23 February 1962. She stayed for a very short time and left to Reruta Nairobi, in 20 May 1963. Her position was taken by Sr. M. Monica CPS in 15 August 1966 up to 1972 when she left to Reruta Nairobi Kenya in 15 March 1972. Later she came back to Tanga and taught in Kifungilo Secondary Girls School. In 15 April 1972 Sr. Victima COLU, was appointed assistant Mother General, the first from COLU and in charge of 27 Noviciates up to 1976 when she retired because of her health. Then Sr. M. Cleopha took her position in 22 February 1976 up to 1978 when Sr. Mathias Mseke took over up to 1995 when she handed over to Sr. Regina Malya.

In 1970 COLU got her Mother General. This was Sr. Inviolata Mndeme.