This issue of Glasnik Matematički is devoted to its founding editor Sibe Mardešić on the occasion of his 80-th birthday. Thus the present editors of Glasnik Matematički wish to thank Professor Mardešić for the founding of our first journal entirely devoted to mathematics, as well as for his participation in the journal as an editor, author, referee and as the member of our mathematical community who has been keeping an eye on Glasnik Matematički all the time.

Sibe Mardešić was born on June 20, 1927, in Bergerdorf (near Hamburg, Germany), where his parents temporarily resided. He lived there only a short time before his family moved to Chile. Due to economic crisis the family returned back to Split, Croatia, in 1930, where he completed elementary school and high school. After WW2 he enrolled in the University of Zagreb taking mathematics as his major. He started with research as an undergraduate student and has been involved in it to this day. After having completed his undergraduate degree he took a position of an assistant at the Department of Mathematics of the University of Zagreb, advancing there through all academic positions until his retirement in 1991.

As a mathematician he is a topologist. Even more, he is a
self-taught topologist, who began his research in algebraic
topology, but his later work ranges through all main branches of
topology. The algebraic topology results obtained in his doctoral
dissertation *Certain homological properties of some function
spaces* were soon followed in the joint work with Pavle Papić
by results in general topology. Dimension theory was then enriched
by the *factorization theorem* of maps which is, in
present-day texts on dimension theory, usually called the
*Mardešić Factorization Theorem*. He also made
significant contributions to the continua theory, for instance his
striking example showing that the Hahn-Mazurkiewicz Theorem does
not extend to the nonmetric case.

When Borsuk first introduced the new theory, later named
*Shape Theory*, Mardešić immediately saw what a
significant advance this was. In collaboration with Jack Segal he
developed an alternative approach to shape theory based on inverse
systems. Today this approach bears the namee "ANR-system approach
to shapes". That approach has quickly turned out to be very
convenient in attacking different questions which have been
naturally arising in the new theory. The shape theory blossomed
during the next decades, its development greatly owing to
Mardešić's many contributions.

Mardešić established many fruitful collaborations with fellow topologists during his career. Perhaps the most fruitful one was with Jack Segal. Their book on shape theory (S. Mardešić and J. Segal, Shape Theory, North-Holland Publishing Co., Amsterdam-New York-Oxford 1982. ISBN: 0-444-86286-2.) has become a standard reference and resource for the subject. Mardešić continues to produce results in this area. In addition to a sequence of research papers, he published a book on strong shape and homology (Sibe Mardešić, Strong Shape and Homology, Springer-Verlag, Berlin-Heidelberg-New York 2000. ISBN: 3-540-66198-0.).

Alongside with research, he devoted his efforts to teaching
topology and encouraging research. In 1961 he founded, together
with P. Papić, the *Topology Seminar* of the University
of Zagreb. In the Seminar we learned topology, presented new
results, hosted topologists from abroad etc. Let us mention that
50 graduate students obtained their Master's Degree through the
work in the Seminar.

In recognition of his work, professor Mardešić received highest awards: Republic of Croatia Award "Ruđer Bošković" (1965); City of Zagreb Award (1978); Republic of Croatia Award for his entire scientific work (1990). He is a member of the Croatian Academy of Sciences and Arts and the Academia Europea.

**Guest Editors: Ivan Ivanšić and Šime Ungar**