South Africa's President Cyril Ramaphosa paid tribute on Thursday tothe late Zulu King Goodwill Zwelithini, who reigned for more than five decades. 

Zwelithini was buried early Thursday as the Zulu nation mourned their longest serving monarch, local media reported.

"On behalf of the people of south Africa I express my deepest condolences to the royal family and the Zulu nation," Ramaphosa said during the late king’s memorial service.   

"“The king is not dead, because kings don’t die. Their spirits live with us.” 

Ramaphosa also praised the late king's efforts in fighting AIDS, gender-based violence and inequality. 

Zwelithini died at age 72 last week in the eastern city of Durban, after weeks of treatment for a diabetes-related illness. 

'Planting' the late king

His remains were laid to rest at his birthplace, the small southeastern town of Nongoma in KwaZulu-Natal province.

A select few men reportedly conducted the intimate ceremony, referred to as "planting", behind closed doors.   

A day before his burial, Zulu mourners paid tribute to their late leader, wearing traditional leopard skin, dancing and parading as they accompanied his body to the royal palace.

A 'controversial' king

Zwelithini was the longest-serving Zulu king in history, reigning for more than five decades.

His role was largely spiritual and ceremonial, and although he had received criticism from South African authorities, he kept his popularity among the Zulu people. 

The late king had controversies with the South African government as he threatened to have his community boycott elections before. He also had a row over his Ingonyama Trust, which managed 3 million hectares (7.4 million acres) of communally-owned land.

Traditional leaders have been constitutionally recognized since the end of the apartheid in South Africa.