Melbourne - There have been many changes among the team line-ups for the new Formula One season which begins in Melbourne at the weekend.
Some drivers have switched teams, some are making their debuts while others have been dropped. A guide to the new grid.
- Mercedes: Lewis Hamilton (GBR), Valtteri Bottas (FIN) -
After claiming their fifth consecutive constructors championship in 2018, and with Briton Hamilton winning the driver's title for a fifth time, and second in a row, dominant Mercedes is one of only two teams to retain the same line-up. Finland's Bottas will be hoping to overshadow his illustrious teammate and add to his three Grand Prix wins.
- Ferrari: Sebastian Vettel (GER), Charles Leclerc (MON) -
Monaco's Charles Leclerc has been parachuted in from Sauber to partner Germany's four-time champion Vettel after a breakthrough rookie season as they work to break the Mercedes stranglehold. Long-time Ferrari linchpin Kimi Raikkonen has gone the other way to rejoin a Sauber team - now named Alfa Romeo - where the Finn started his career in 2001.
- Red Bull: Max Verstappen (NED), Pierre Gasly (FRA) -
Australian Daniel Ricciardo's shock decision to leave Red Bull after five years for Renault has seen France's Gasly promoted from Toro Rosso, who gave him his first Formula One start in 2017. He joins his old karting rival Verstappen, with Red Bull having high hopes of "Mad Max" winning the title.
- Renault: Daniel Ricciardo (AUS), Nico Hulkenberg (GER) -
Seven-time race winner Ricciardo's move to Renault on a two-year deal was the biggest surprise in the paddock and he is hoping engine enhancements will deliver him a car that can close the gap on Mercedes, Ferrari and Red Bull. Dependable and experienced German Hulkenberg begins his third year with the team.
- Haas: Roman Grosjean (FRA), Kevin Magnussen (DEN) -
The American team have made steady progress since their 2016 debut and, along with Mercedes, are one of two teams to stick with the same line-up. It follows a promising 2018 in which they finished fifth in the constructors' championship. Grosjean and Magnussen are in their third season together.
- McLaren: Lando Norris (GBR), Carlos Sainz Jr (ESP) -
It's all change for the underperforming British team with veteran Fernando Alonso leaving Formula One and Sainz Jr, the son of a double world rally champion, replacing him from Renault. Stoffel Vandoorne was let go, allowing exciting young British talent Lando to take his place for a maiden season aged just 19.
- SportPesa Racing Point: Sergio Perez (MEX), Lance Stroll (CAN) -
Canadian young gun Stroll, 20, moves over from Williams to the former Force India team now under new ownership, despite a less than impressive 2018 when he was hampered by a poor car. He joins incumbent Perez, who scored a podium finish (third) in Azerbaijan last year behind Hamilton and Raikkonen, and a fifth in Belgium.
- Alfa Romeo: Kimi Raikkonen (FIN), Antonio Giovinazzi (ITA) -
Finn Raikkonen brings huge experience to the team, formally known as Sauber, replacing Leclerc who has moved into his seat at Ferrari. He is joined by Ferrari academy graduate Antonio Giovinazzi, who races at the top level for a first full season with Marcus Ericsson relegated to reserve driver.
- Toro Rosso: Alexander Albon (THA), Daniil Kvyat (RUS) -
Thai-British driver Albon, 22, has won promotion from Formula 2, where he had four wins last year, replacing Brendon Hartley, while Russian comeback kid Kvyat returns for a third spell at Toro Rosso after spending last year as Ferrari's development driver. He takes Pierre Gasly's seat.
- Williams: George Russell (GBR), Robert Kubica (POL) -
Determined Pole Kubica has been out of Formula One for eight years and makes an unlikely comeback after suffering multiple injuries in a rallying crash. He is joined by Britain's Formula 2 champion Russell with the pair tasked with reversing the team's recent decline. Williams finished last on the points table in 2018.