HOUSTON (AFP) - Past presidents, family and friends came together on Saturday (April 21) to bid a tearful farewell to Barbara Bush, the matriarch of one of America's most prominent political dynasties, at a funeral service in Texas.

Bush, who died Tuesday aged 92, was wife to the 41st US president and mother to the 43rd. She was remembered for her friendship, her wit and her strength.

The invitation-only service at St Martin's Episcopal Church in Houston was attended by four former presidents: George H.W. Bush - Barbara's husband of 73 years - their son George W. Bush, Bill Clinton and Barack Obama, as well as other former senior officials.

First Lady Melania Trump attended but her husband President Donald Trump did not, with the White House saying his decision to stay in Washington was taken "to avoid disruptions due to added security."

"My thoughts and prayers are with the entire Bush family," Trump wrote on Twitter, saying he planned to watch the funeral ceremony.

The public had the opportunity to pay their respects to Barbara Bush the previous day at a visitation the previous day.

"Barbara Bush filled our lives with laughter and joy," her son Jeb, a former Florida governor and presidential candidate, said during the service.

"In the case of our family, she was our teacher and role model on how to live a life of purpose and meaning," he said.

Known for her trademark faux pearls - which Jeb mentioned in his eulogy - and tart-tongued comments about life in and out of Washington, Barbara Bush was in many ways a figure more popular among ordinary Americans than her high-flying husband and sons.

'STRONG, FUN AND FEISTY'

She met her husband-to-be at age 16 when she was a schoolgirl and he was a student at an elite Massachusetts preparatory school, and they married in 1945 while he was on leave from wartime service.

Bush made history as one of just two women to be wife and mother to US presidents. Abigail Adams, who died in 1818, was the other.

"She was smart, strong, fun and feisty," said Susan Baker, wife of George H.W. Bush's secretary of state and chief of staff.

And she was "a remarkable and selfless companion to her husband George," Baker said.

Bush was her husband's companion and advisor as they traveled the world, moving multiple times as he rose from Texas oil man to congressman, US ambassador to the United Nations and envoy to China, director of the CIA and eventually to the vice presidency and the White House.

But she made a point of avoiding direct involvement in politics, and the posturing that comes with it - gaining a reputation for toughness, wry humor and straight-speaking.

Having undergone heart surgery in 2009, she was treated for years for Graves' disease, a thyroid condition. As her health failed in recent days, she was moved into comfort care at her home in Houston.

Barbara Bush is survived by five children, 17 grandchildren and seven great-grandchildren. She lost a sixth child - daughter Robin - to leukemia as a toddler.

She will be buried at the George Bush Presidential Library in College Station, Texas.