This Symposium began with a proposal for a meeting to honour Emer itus Professor Robert Hanbury Brown on the occasion of his 80th birthday. He requested that any such meeting should be on a topic that would be of benefit to the Sydney University Stellar Interferometer (SUSI) program. With SUSI and several other high angular resolution instruments either in operation or coming on line within the next decade, and with advances in astrometry, spectroscopy and in theoretical models of stellar atmospheres and interiors, it appeared to be both appropriate and timely to hold a symposium on...