South African Archbishop Desmond Tutu, who fought to end the country’s apartheid, has passed away in Cape Town. He was 90 years old.

In a statement announcing his death on Sunday (Dec. 26), South African President Cyril Ramaphosa offered his condolences to Tutu’s family and called him “a patriot without equal.”

“A man of extraordinary intellect, integrity and invincibility against the forces of apartheid, he was also tender and vulnerable in his compassion for those who had suffered oppression, injustice and violence under apartheid, and oppressed and downtrodden people around the world,” Ramaphosa said.

Becoming the first Black African Archbishop of both Johannesburg and later Cape Town, Tutu was revered for his anti-apartheid and human rights activism. He was named chair of South Africa’s Truth and Reconciliation Commission after apartheid — South Africa’s system of racial segregation and white minority rule — ended and formerly imprisoned Nelson Mandela became president.

“[Tutu] was larger than life and for so many in South Africa and around the world his life has been a blessing,” the Nelson Mandela foundation said, calling his loss “immeasurable.” “His contributions to struggles against injustice, locally and globally, are matched only by the depth of his thinking about the making of liberatory futures for human societies.”

Tutu’s advocacy for human rights and nonviolent activism led him to win many honors, including the Nobel Peace Prize and the Presidential Medal of Freedom, the latter of which was given to him by Former President Barack Obama in 2009.

“Archbishop Desmond Tutu was a mentor, a friend and a moral compass for me and so many others,” Obama wrote on Twitter after his death. “A universal spirit, Archbishop Tutu was grounded in the struggle for liberation and justice in his own country, but also concerned with injustice everywhere. He never lost his impish sense of humor and willingness to find humanity in his adversaries, and Michelle and I will miss him dearly.”

Tutu’s cause of death was not disclosed. He was diagnosed with prostate cancer in 1997 and, after receiving treatment, the cancer reappeared in 2005. Tutu was also repeatedly hospitalized in 2015 and 2016 for health issues linked to the cancer.

See tributes to Tutu’s incredible life and legacy on Twitter below.