Cardinal Aquilino Bocos Merino, C.M.F., was born on 17 May 1938 in Canillas de Esgueva, Valladolid, Spain.

He completed his studies at the seminaries of the Claretian Missionaries.

He gave his religious profession in 1956 and was ordained a priest in 1963.

He graduated in philosophy from the Pontifical University of Salamanca, and holds a diploma in clinical psychology.

During his ministry he has held the following positions: from 1964 to 1967, spiritual director of the Colegio Mayor Maronita in Salamanca; from 1967 to 1980, spiritual director of the Claretian Theologate, and professor in various educational centres of the Congregation; director of the Vida Religiosa Magazine; co-founder of the Theological Institute of Religious Life in Madrid and director of the Regina Apostolorum School; from 1980 to 1985 he was elected as provincial superior of the Claretian Missionaries of Castilla. From 1985 to 1991, he served as general counsellor of the Claretian Missionaries. In 1991 he was elected as superior general of the Claretians for two terms. During this time he participated as a member of the Union of Superiors General (for two terms).

In 1994 he participated in the Synod for Consecrated Life; in the Second Special Meeting for the Synod of Europe (1999) and in the Eleventh Meeting of the Synod of Bishops (2002).

From 1994 to 2004 he was commissioned to participate as a member of the Congregation for Consecrated Life.

He has published several books and articles for numerous magazines.

Created and proclaimed Cardinal by Pope Francis in the consistory of 28 June 2018, of the Diaconate of Santa Lucia del Gonfalone.