Fellowes was joined by singer Lulu, actor Edward Fox and members of Rees' family who gathered at St Paul's Church in the Knightsbridge area of London to celebrate her life on Thursday (27Sep12).
The British star, best known for her role in 1970s U.K. TV series Poldark, lost her battle with pancreatic cancer in July (12) at the age of 63.
Fellowes told the congregation, "She was a fighter. Not for nothing was her nickname hand grenade. I have only had four real rows since I was grown up and two of them were with Angharad. We once emptied a restaurant, when the other patrons started to ask for their bills, or to be seated elsewhere to get away from the noise we were making.
"But, if her fierceness made her a frightening opponent, it was a wonderful quality to have on your side. Because, if there was one thing she was superb at, it was friendship, and not just sympathetic friendship but hard-working, useful, practical assistance."
He also praised Rees for balancing her career with family life, adding, "She was determined that it would be her children who took precedence. She was not prepared to pay the price of being a great actress if it meant that her family would have to pay it with her.
"She was anxious, I think, that she should not be defined, entirely, as the star of a popular series, as one half of a golden couple, as a mother and hostess, although she excelled in all of these."
Rees, best known for her role in 1970s U.K. TV series Poldark, lost her battle with pancreatic cancer on Saturday (21Jul12) at the age of 63, and Barber has been left stunned by her passing.
In a post on her Twitter.com page, she writes, "Oh Angharad Rees so upsetting. Beautiful in every way."
Fellow actress Ruth Madoc has also remembered her friend, saying, "She was a lovely, gentle woman and very pretty. Poldark was a landmark series which everyone remembers so well."
The Welsh star, best known for her role in 1970s U.K. TV series Poldark, passed away on Saturday (21Jul12).
A statement released by her family reads, "The family of Angharad Rees (McAlpine) are deeply saddened to announce that Angharad passed away peacefully with her family at her bedside in London, after a long battle with pancreatic cancer.
"She will be greatly missed by her family and friends."
Rees played Demelza in Poldark, a period drama based on Winston Graham's novels, and also appeared in the horror film Hands Of The Ripper.
She was married to late Dynasty actor Christopher Cazenove for more than 20 years before they divorced in 1994, and later went on to marry David McAlpine.
The British star, best known for his role as Ben Carrington in the glamorous 1980s soap opera, passed away in a London hospital on Wednesday (07Apr10).
Cazenove was taken ill at the end of February (10) and admitted to St Thomas' Hospital in the British capital, where doctors diagnosed him with septicaemia. He spent over a month in an intensive care unit fighting for his life before his death this week (07Apr10).
Cazenove's passing comes just days after the death of his onscreen brother John Forsythe, who played Blake Carrington in the show.
Forsythe died last Thursday (01Apr10) at the age of 92.
A statement from Cazenove's agent Lesley Duff confirms the sad news: "Christopher died peacefully on April 7 surrounded by his loved ones having contracted septicaemia at the end of February. Despite a valiant fight and the untiring efforts of the wonderful team at St Thomas', he was overwhelmed. All who knew and loved him will be devastated by the loss of this incredible man who touched so many lives."
Cazenove's first major role came in 1970s U.K. TV show The Regiment, and he went on to star in a string of films before landing the part that made his name, playing opposite Joan Collins in Dynasty between 1986 and 1987.
The actor went on to star in notable movies including 1990's Three Men and a Little Lady, the sequel to Three Men and a Baby, and 2001's A Knight's Tale, in which he played the father of Heath Ledger's character.
He was last seen in British TV series Hotel Babylon in 2009.
Cazenove is survived by his son Rhys, from his marriage to actress Angharad Rees. The former couple's eldest son, Linford, was killed in a car crash in 1999. Cazenove was in a relationship with girlfriend Isabel Davis, who he had been dating since 2003, at the time of his death.
The star, who played Ben Carrington in the popular 1980s show, was admitted to St Thomas' Hospital in London after becoming unwell during a flight from Los Angeles, reports Britain's Sunday Mirror.
The 66 year old has spent the last two weeks seriously ill with septicaemia, and his former wife, actress Angharad Rees, and his son are with him at his bedside.
A representative for Cazenove says, "He has been very poorly, but he is making a slow and steady recovery."