Jennifer Garner and daughter Violet support Ben Affleck at Senate hearing

Ben Affleck attended a US Senate hearing on Thursday (March 26), where he made a passionate speech about the need for foreign aid in Africa. In the audience, the actor' wife, Jennifer Garner, and eldest daughter Violet looked on proudly as the Batman star spoke at the US Senate Appropriations Subcommittee on State, Foreign Operations and Related Programs.

Forty-two-year-old Ben, who founded the Eastern Congo Initiative in 2010, sat next to Microsoft founder Bill Gates to testify about the cause.

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Ben Affleck was supported by his wife and eldest daughter at a US Senate hearing

Despite the serious nature of the testimony, Ben made a light-hearted quip when he called out Vermont senator Patrick Leahy, who is a known Batman fan and has had small guest appearances in three of the superhero films.

"I would be remiss not to recognize my co-star in Batman," Ben said. "Your role was marginally smaller than mine, but I understand you were quite good."

Jennifer Garner proudly looked on while Ben Affleck spoke

Following his testimony, nine-year-old Violet was seen congratulating her dad, while Jennifer also gave her husband a supportive pat on the back.

The couple's youngest children – six-year-old Seraphina and three-year-old Samuel – were not present at the hearing.

Jennifer and Ben are said to have one of the strongest marriages in Hollywood, and are fast approaching their tenth wedding anniversary. Dallas Buyers Club star Jennifer has previously said that the secret to their success is being "mindful" of each other's needs and careers.

Ben Affleck was supported by his eldest daughter Violet

"We're definitely in a very mindful place where we're making an effort to be together, do things at the same time, and be loving," she told InStyle.

The 42-year-old also said that she and Ben try to take it in turns to work while one of them stays at home to look after the children.

"Ben is super busy and I'm super happy for him," she said. "I chose to stay home this year and just said, 'Go for it babe. Do it all. Do Gone Girl, do Batman, do The Accountant. Do everything.'

"I want that for him and I'm happy for him. And he says the same to me. Except that he's really busy. But he understands that when I really have to do it, we figure it out."

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