Dr. Geoffrey Lewis is an internationally acknowledged student who deals mainly with the postal history of Spain and its colonies.  His Monograph and journal articles on the Spanish Philippines have an importance in regards the postal history of adjacent areas in Asia.

He has also written journal articles on a range of pre twentieth century postal history topics.  Dr Lewis has also fostered research in the NSW Philatelist, published by the Philatelic Society of New South Wales where he as been President for over 10 years.

He has formed significant exhibits of Postal History on the Spanish period of Philippines and Cuba as well as mail through Spain.  The research shown in each of these exhibits has helped them attained high awards at International level.  He is one of a few international collectors who have been invited to be a member of the Spanish Academy of Philately.