King Harald, who emerged from the shadow of his own well-loved, extrovert father to become a reformer during more than three decades on the throne, died on Friday at the age of 89.
His son Haakon, dressed in a black suit, white shirt and black tie, praised Harald as a warm family man in a recorded televised speech at the palace.
"My dear father, thank you for being such a good dad for Martha and I," he said, referring to his sister, Princess Martha Louise.
"I am going to miss him. I am going to miss his laughter. I am going to miss his good-natured way to meet people and situations," he continued, sitting behind a desk, with a portrait of a smiling Harald to his left.
He noted that Saturday should have been the celebration of the 58th wedding anniversary of Harald and Queen Sonja, who survives him.
"Congratulations on your wedding anniversary, dear Mummy," Haakon said, his voice appearing briefly overtaken by emotion.
Haakon stressed he would do things his own way, like his father did before him, and reiterated the foundations of Norway as a constitutional monarchy, embodied by the oath he will take in parliament on Tuesday to protect the country's constitution and laws.
"We believe in our system of self-governance - and in democracy. We believe in a society built on the rule of law - where every individual has equal worth," he said.
Haakon automatically became king upon his father's death under Norway's constitutional monarchy. There will be no coronation as they were abolished by parliament in 1908.
"We believe in a Norway where there is room for everyone. We shall feel the strength of our community - and know deep within ourselves that we are one people," he said.
At the end of his speech, outside the palace, mourners who had been watching on their mobile phones broke into spontaneous applause.
Since Harald's passing, people have streamed in their tens of thousands to say goodbye to the late king at the royal palace, where he lies in state, with many well-wishers remembering his sense of inclusiveness and tolerance.
Flags were flying at half-mast throughout the country and portraits of the late king in gala uniform could be seen at bus stops, trams and metro stations to shops, offices and public buildings.
The main avenue in central Oslo, Karl Johan, was tightly packed with people from all walks of life heading towards the palace, clutching flowers, handwritten cards, drawings and small national flags.
