The impressive career of George Blasse in the field of luminescence started in 1964. Triggered by the discovery of YVO₄:Eu³⁺ as red phosphor in cathode ray color TVs the management of Philips Research decided to re-establish the luminescence group and George Blasse was asked to lead the group. Very productive years followed in which George discovered many new phosphors, including YAG:Ce³⁺. In 1970 he made an unusual career switch and accepted the position of professor of Solid State Chemistry at Utrecht University. George Blasse led a highly successful research group for over 25 years and became internationally recognized for his research on luminescent materials. During his career he frequently attended ECS Meetings which has been and continues to be a place where reseaerchers from universities and industry in the field of luminescence materials meet and new phosphors and concepts are presented. I vividly remember attending the ECS meeting in Chicago in 1988 together with George.

George Blasse combined groundbreaking fundamental discoveries with societal relevance. He had a deep and also intuitive understanding of luminescence phenomena and often relied on clever chemical variations in host composition and structure to obtain insight in the underlying physics. Simple guidelines and clear design rules based on systematic and careful research of a wide variety of materials were discovered, explaining spectral variations and trends, for example in thermal quenching of luminescence for Eu³⁺. The constant energy difference between fd states of different lanthanides was pioneered by George Blasse and later became the basis for the now widely used Dorenbos model. Another area where the work of George Blasse was instrumental involved energy transfer and energy migration phenomena. He was able to translate the somewhat complex theoretical papers as those by Förster and Dexter into simple models and equations to understand and quantify energy transfer processes. George Blasse also made important contributions in understanding of the optical properties of s² ions like Pb²⁺, Bi³⁺, Sb³⁺ and Sn²⁺. In recent years this work of George receives increasing attention in the light of extensive work on luminescence of these ions in double perovskites. In this presentation I will share memories and highlight the great contributions of George Blasse to our field.