his biggest hit songs, "It Don't Come Easy" and "Back Off Boogaloo", although he only accepted a credit for "Photograph", which they wrote together in France. Starting with the Ringo album in 1973, Starr shared a songwriting partnership with Vini Poncia. One of the pair's first collaborations was "Oh My My". Over half of the songs on Ringo the 4th were Starkey–Poncia compositions, but the partnership produced just two more songs, released on Bad Boy in 1978. Personal life Starr met hairdresser Maureen Cox in 1962, the same week that he joined the Beatles. They married in February 1965. Beatles manager Brian Epstein was best man and Starr's stepfather Harry Graves and fellow Beatle George Harrison were witnesses. Their marriage became the subject of the novelty song "Treat Him Tender, Maureen" by the Chicklettes. The couple had three children: Zak (born 13 September 1965), Jason (born 19 August 1967) and Lee (born 11 November 1970). In 1971, Starr purchased Lennon's home Tittenhurst Park at Sunninghill in Berkshire and moved his family there. The couple divorced in 1975 following Starr's repeated infidelities. Maureen died from leukaemia at age 48 in 1994. Starr met actress Barbara Bach in 1980 on the set of the film Caveman, and they were married at Marylebone Town Hall on 27 April 1981. In 1985, he was the first of the Beatles to become a grandfather upon the birth of Zak's daughter Tatia Jayne Starkey. Zak is also a drummer, and he spent time with the Who's Keith Moon during his father's regular absences; he has performed with his father during some All-Starr Band tours. Starr has eight grandchildren: two from Zak, three from Jason, and three from Lee. In 2016, he was the first Beatle to become a great-grandfather. Starr and Bach split their time between homes in Cranleigh, Los Angeles, and Monte Carlo. He was listed at number 56 in the Sunday Times Rich List 2011 with an estimated personal wealth of £150 million. In 2012, he was estimated to be the wealthiest drummer in the world. In 2014, Starr announced that his 200-acre Surrey estate at Rydinghurst was for sale, with its Grade II-listed Jacobean house. However, he retains a property in the London district of Chelsea off King's Road, and he and Bach continue to divide their time between London and Los Angeles. In December 2015, Starr and Bach auctioned some of their