I am an experimental atomic physicist, with interests in positrons, positronium and antihydrogen. I have made contributions to many aspects of the development of physics with low energy positrons and helped to establish positronium beam physics. Since the mid-1980’s I have pioneered the field of antihydrogen physics. I was a founder member of the ATHENA collaboration that first produced cold antihydrogen and later of the ALPHA collaboration. ALPHA has performed several experiments on antihydrogen, including spectroscopic measurements involving ground and excited states, thereby ushering in the era of precision physics with atomic antimatter.