About 100 hostages, living and dead, are thought still to be held in Gaza, most of them taken in the deadly Hamas-led attacks on Israel on Oct. 7, 2023. Thirty-three of them will be released during an initial six-week phase of the cease-fire, including female soldiers and civilians, children, men over 50 and sick and wounded people, according to the agreement.

“The vast majority” of the 33 hostages to be released in the six-week first phase of the cease-fire are alive, an Israeli military spokesman, Lt. Col. Nadav Shoshani, said Sunday in a discussion on social media.

Video released by the Israeli military showed the three hostages being reunited with their families at Sheba Hospital in Israel.

In one clip, one of the returned hostages, Romi Gonen, is surrounded in an embrace by members of her family as they tearfully comfort one another. Yarden Gonen, her sister, who had traveled around the world in the past year to lobby for Romi’s release, jumps up and down in the video as the family hugs. In another clip, another released hostage, Doron Steinbrecher, tearfully embraces loved ones.

Romi Gonen

Ms. Gonen was 23 when she was captured as she was trying to leave the Nova music festival in southern Israel when Hamas attacked. She was speaking at the time to her mother, Meirav Gonen, who said she had been shot and was bleeding.

Last February, Meirav Gonen released a recording of her last phone call with her daughter. She told the Israeli news media that Romi was a strong and happy person who often went to raves.

In the early weeks of the war, her mother expressed concern that Israeli military operations in Gaza could endanger the hostages.

Romi Gonen’s older sister, Yarden, told The New York Times in February that she regularly went to a plaza in Tel Aviv where families of hostages have held vigils.

“None of us is doing anything remotely related to our previous lives,” she said.

Emily Damari

Ms. Damari, 27 at the time she was captured, is the only hostage with British citizenship who was still being held this month. She was taken from her home in Kibbutz Kfar Azza in southern Israel and was seen by a neighbor in her own car, driven by a militant, heading toward Gaza.

Ms. Damari was raised in Israel but traveled to Britain often, according to her mother, British-born Mandy Damari, who was in Israel last month to speak with officials and the news media and to plead for a hostage and cease-fire deal. She said that her daughter had been shot and that she feared for her life, telling the BBC that she had welcomed the threats from President-elect Donald J. Trump that there would be “all hell to pay” if no deal was reached by his inauguration.

Last January, a hostage who had been released from Gaza, Dafna Elyakim, told the Israeli news media that she and her younger sister had been taken into Hamas’s underground tunnels, where they met other female hostages, including Ms. Damari.

On the eve of the first anniversary of the Oct. 7 attacks, Mandy Damari spoke at an event in Hyde Park in London, where she described her daughter as a soccer fan who enjoyed a drink and had “the classic British sense of humor, with a dash of Israeli chutzpah thrown in for good measure.”

On Sunday, Mandy Damari thanked “everyone who never stopped fighting for Emily throughout this horrendous ordeal.” But, she said in a statement, “for too many other families the impossible wait continues.”

The Israeli military also released a picture of Emily Damari and her mother that showed her missing two fingers on her left hand. Ms. Damari was shot in the hand on Oct. 7, 2023.

Doron Steinbrecher

Ms. Steinbrecher, who was 30 when she was captured from her home in Kibbutz Kfar Azza, is a veterinary nurse with Romanian and Israeli citizenship. According to Israeli news media, she was in touch with her family on the kibbutz when the militants attacked, telling her parents that they had smashed her windows and shot into her room.

“They’ve arrived, they have me,” she said in a subsequent voice message sent to friends.

Last January, Hamas released a video clip of Ms. Steinbrecher and two other captives, Daniella Gilboa and Karina Ariev, in which they pleaded for their release.

Last March, on her 31st birthday, the Jewish News Syndicate published an interview with her mother, Simona Steinbrecher, who said that she had looked pale and thin in the video. She said she was concerned that Ms. Steinbrecher was not getting the daily medication she needed, though she did not specify what that was.

“She’s a strong woman, but it’s terrible being there,” Simona Steinbrecher said.

On Sunday, the family of Doron Steinbrecher issued a statement celebrating her release that thanked the Israeli people and expressed gratitude to Mr. Trump “for his significant involvement and support, which meant so much to us.” The statement did not mention President Biden or any Israeli leaders.