Chavez will be mourned by many of the country's poor, who revered the self-styled revolutionary for using the country's oil riches to fund popular housing, health, food and education programs.
And like-minded Latin American leaders like Cuba's Raul Castro, Ecuador's Rafael Correa and Bolivia's Evo Morales lost a close friend who used his diplomatic muscle and cheap oil to shore up their rule.
Chavez died five months after winning an October election, overcoming a resurgent opposition and public frustration over a rising murder rate, regular blackouts and soaring inflation.
He missed his swearing-in for a new six-year term on January 10, but the Supreme Court approved an indefinite delay.
A new election could offer another shot at the presidency to Henrique Capriles, the opposition leader who lost to Chavez in October.
Until picking Maduro, 50, as his political heir, Chavez had never allowed other leaders to emerge within his United Socialist Party of Venezuela (PSUV).
He used the ballot box to consolidate his power and push through policies that drove a wedge into Venezuelan society, alienating the wealthy with expropriations while wooing the poor with social handouts.
Chavez won re-election vowing to make his self-styled 21st century "Bolivarian" revolution "irreversible."
Defense Minister Diego Molero, surrounded by top military officers, said Tuesday that the armed forces would defend the constitution and respect Chavez's wishes.
The opposition had accused Chavez of misusing public funds for his campaign and dominating the airwaves while forcing government workers to attend rallies through intimidation.
His death will particularly affect Cuba's communist regime, whose moribund state-run economy has relied heavily on Chavez's oil generosity.
Under Fidel Castro's mentoring, Chavez became the face of the radical left in Latin America, with regular diatribes against US "imperialism" and the forging of ties with regimes at odds with Washington in Syria, Libya and Iran.
But despite tense relations with the United States, Chavez continued to export one million barrels of oil per day up north.
