The collection of papers contained in this book is intended to be a warm homage to Antonio Plans, on the occasion of his 65 th. birthday, which at present in Spain marks the point of retirement from academic undergraduate teaching.

We have chosen the topic of Banach Spaces since it has been the center of his Mathematical interests for the last few years. The papers included have been written by friends, or students of Professor Plans, or by a few of the mathematicians who have been in touch with him for scientific reasons.

We feel sorry to restrict ourselves to Just one topic, since there are many colleagues who, for sure, would have liked to write something for this event. As a matter of fact Professor Plans is widely known by his results on Knot Theory, a field he worked on at the beginning of his research career, and an active field of research today.

We now briefly sketch Professor Plans' personality and Mathematical work. The latter will necessarily be incomplete since at this very moment he is vigorously active and producing new results. For example, he is at present giving advice to four students for their doctoral dissertations.

Born in Madrid, he was the sixth of seven children. He was brought up in the cheerful atmosphere that characterizes such large families.

Soon after there came harder times; the social environment of his country was full of tension, the religious persecution started, and the growing insecurity and anxiety ended up in the civil war (1936–39).