Born in Tanzania, Millen Happiness Magese won the Miss Tanzania crown in 2001, competing days after contracting malaria, and powering through a condition she would later reveal had plagued her since girlhood. After her reign, she relocated to South Africa and built one of the most enduring international modelling careers ever to emerge from East Africa. She became the first Tanzanian model to be signed by Ford Models in New York. She went on to walk runways across Africa, Europe, America, and Asia, working with designers including Ralph Lauren and Karen Millen.

After years of battling severe endometriosis and undergoing 13 surgeries, Millen went public with her diagnosis and, through her foundation, she spearheaded campaigns including Many Faces of Endo and Speak Out!, and initiated training programmes to equip Tanzanian doctors better to diagnose and treat endometriosis. She also advocates for gender equality through improved access to education and reproductive health services, with a long-term plan to build schools for children in rural Tanzania.

In 2015, BBC named her one of Africa's Unsung Heroes. She is also a recipient of the BET International Global Good Award, a recognition that places her alongside some of the most impactful humanitarians on the continent.