"He was the man who created the name Jerusalem as a real place, not as a town where things were blown up but a place where people could live together, even as Arabs and Jews," said Yisrael Kimche, who worked under Kollek as director of policy planning for the city.
"He established modern Jerusalem more than anyone else," said Kimche, who is currently a researcher at the Jerusalem Institute of Israel Studies.
Kollek, who grew up in Vienna and came to what was then British Mandate Palestine in 1935 as a young man, was considered one of the last of the generation of Israel's founding fathers. He was known for expertly navigating the divide between Jerusalem's diverse populations -- Jewish and Arab, religious and secular.
He had been in office for just two years when the Six-Day War broke out in 1967, leading to the reunification of the city.
"Jerusalem's people of differing faiths, cultures and aspirations must find peaceful ways to live together, other than by drawing a line in the sand," Kollek once said.
Kollek forged strong ties with American Jewish and other Diaspora leaders throughout his tenure and was adept at raising funds for his beloved city. Former New York City Mayor Ed Koch called Kollek, his longtime friend, "the mayor of all mayors." "Everybody loved him, including everyone in the city of Jerusalem -- even when they disagreed with him, and that ran the gamut from the Jews to the Arabs to anyone," Koch said.
Theodor Kollek was born in 1911 in a small town in Hungary, and as a young child moved to Vienna. There he became active in Zionist youth movements under the influence of his father, a staunch Zionist who named his son after Theodor Herzl.
During the Israeli War for Independence, Kollek helped buy weapons and ammunition for Israel's fledgling militia, the Haganah. He also met with Adolf Eichmann soon after World War II broke out and persuaded him to allow 3,000 Jewish youth passage to England.
Kollek became a confidante of David Ben-Gurion and worked as the chief aide to the country's first prime minister from 1952 to 1965. In 1965, Ben-Gurion asked Kollek to run for mayor as part of his political party. Kollek balked initially, figuring he had no chance to win. Much to his own surprise, he was elected. He was defeated 28 years later in 1993 by a Likud Party leader named Ehud Olmert.
Once the traditionally Arab eastern part of Jerusalem became part of the city in 1967, Kollek set ambitious plans to build Jewish neighborhoods around it to keep the city Israeli. He also worked to bring municipal services to the Arabs who under Jordanian rule had lived in some neighborhoods without sewage, running water and telephones.
But the city's Arab population often said it felt neglected, even by the man championed for his vision of a mosaic city. Palestinians comprise about one-third of the city's 700,000 residents.
Former aides and Kollek himself would say in later years that not enough money and support was channeled to neighborhoods in the eastern sector, which have consistently received less funding than Jewish areas in the west. Kollek did, however, protest moves by Jewish right-wing groups to settle in areas of eastern Jerusalem, claiming such moves were provocations in an already tense city.
Kollek was known for his relentless pace and his efforts at building up the city. Virtually every cultural institution in the city was a result of his influence and fundraising, from the Israel Museum and the Biblical Zoo to the Jerusalem Theatre. He transformed large swaths of land into parks with tulip beds and walkways and promenades to take in the city's famous views.
"The city is definitely mourning his loss," said Marlene Post, president of Hadassah International. "He was greater than life. You can definitely say that he was a modern-day Herod. He built the Knesset building, the Jerusalem Museum and Hebrew University on Mount Scopus."
Kollek also cultivated archaeological projects and led reconstruction efforts of the Old City's Jewish Quarter.
Kollek was praised for adeptly juggling the needs of the city's Jewish population -- secular and religious. He approved the building of neighborhoods for ultra-Orthodox Jews, or Charedim, far from the main roads so they would not be affected by those driving on Shabbat. He also fought for a sports stadium, which won the praise of secular Jerusalemites. To quell religious protests, he promised a nearby shopping mall would remain closed on Shabbat.
Kimche said he mourns the Jerusalem that his former boss was trying to create -- an open, tolerant and cosmopolitan city.
Today's Jerusalem, he said, feels like a more extreme place. The successive Palestinian uprisings have polarized Jewish and Arab populations, and the growing size and strength of the Charedim have led to confrontations over religious pluralism.
In his role as chief caretaker, he was an outstanding fundraiser -- renowned for his ability to raise funds among Diaspora Jews.
"He was always irascible, energetic and had a driving force to build Jerusalem into the capital he felt Israel deserved," said Seymour Reich, a past chairman of the Conference of Presidents of Major American Jewish Organizations.
"There was only one Teddy Kollek, and modern-day Jerusalem owes a debt to him in terms of its structure and its role in world Jewry," Reich said. "We need more Teddy Kolleks."
JTA staff writer Jacob Berkman in New York contributed to this report.