Phil and Grant Mitchell arrived in Albert Square, Walford, in February 1990. They were new to the area and set up a garage in an arch in the railway viaduct. They bought a flat in Albert Square and made The Queen Victoria their local. They initially came across as 2 cheeky lads even if they were unpredictable. They were a bit dodgy, and got involved in a few scrapes, and even sucked Arthur Fowler into one of their schemes, although Phil took the blame. While they were handy with their fists, Phil and Grant were not out and out villains, and a far cry from being crime lords, they were just 2 dodgy mechanics. Grant begun dating Sharon Watts. However Grant's darker side came out when he found that ex policeman Eddie Royle flirted with Sharon Watts. Grant beat him up badly in the Vic. Later on Eddie was found dead and Grant was a suspect until Nick Cotton owned up.
In December 1991, Sharon and Grant married. However, she was on the constant receiving end of his mood swings and rages. Often, the calmer Mitchell brother, Phil had to restrain Grant. The PTSD from his army days was coming out, from when he had accidentally shot an unarmed boy and had watched friends get killed. This is what made him have nightmares and made him prone to violent rages. Due to this, Grant was judged harshly, especially by Pauline Fowler.
In 1992, Grant wanted a child but found out Sharon was still taking the pill so he smashed up the Vic and the disappeared. While Grant was away, Sharon sought comfort in Phil. They ended up sleeping together. They both regretted it and covered their tracks. Grant torched the Vic in an insurance scam but the claim was denied. Sharon found out what Grant had done so she left him. Grant had yet another violent rage when Sharon returned to seize control of the pub. The police were called by Michelle and Grant attacked the police and was locked up. Phil and Sharon rekindled their affair but ended it when Grant was released from prison in May 1993.
Grant then appeared to turn over a new leaf and rekindled with Sharon. Phil begun dating Kathy and when her ex Richard Cole spread nasty lies about her, for once it was Grant the sensible one and Phil the violent one when Grant restrained Phil from battering Cole in the Vic toilets. As usual, Cole was so calm and flippant about it. Grant did however give Aidan Brosnan a bit of a slap when he found he had nicked from him.
In early 1994, Phil bought one of cash strapped Frank Butcher's flats and Frank's share in the Bridge Street Cafe for a pittance. Phil claimed he was not rich either. He felt he owed Frank a favour. He initially suggested that if the car lot is insured, maybe there should be a fire. When Frank's money worries worsened, he called in the favour and Phil said "You scratch my back and I commit arson for you is that it" in a cheeky way. Phil agreed and they both agreed to cover their tracks.