Answer by taking a quote from the following article:

Marc Marquez Alenta (born 17 February 1993) is a Spanish Grand Prix motorcycle road racer and four-time MotoGP world champion. Marquez races for Honda's factory team since his MotoGP debut in 2013. Nicknamed the "Ant of Cervera", he is one of four riders to have won world championship titles in three different categories, after Mike Hailwood, Phil Read and Valentino Rossi. Marquez won the 2010 125cc World Championship, the 2012 Moto2 World Championship, and the 2013, 2014, 2016 and 2017 MotoGP World Championships.

Born in Cervera, Catalonia, Spain, Marquez made his championship debut on 13 April 2008 at the 125cc 2008 Portuguese Grand Prix at the age of 15 years and 56 days. He is the youngest Spanish rider to take a pole position or a podium in a motorcycle racing world championship.  Marquez achieved his first podium on 22 June 2008 at the British Grand Prix. For 2009, as a factory KTM rider, at the French Grand Prix achieved his first pole position at the age of 16 years and 89 days. He also took pole for the 2010 Spanish Grand Prix but the exhaust pipe fell off on the opening lap and went under the rear wheel, causing Marquez to crash and injure his shoulder. His first win was on 6 June 2010 at Mugello. Further victories at Silverstone, Assen and Catalonia in the next three races made Marquez the youngest rider to win four successive races. His fifth win in succession at the Sachsenring was Derbi's 100th victory in Grand Prix racing, and Marquez became the first rider since Valentino Rossi in 1997 to win five successive races in 125cc racing.  He was less successful in the following races, dropping to third in the standings at one point behind Nicolas Terol and Pol Espargaro after being involved in an accident with Randy Krummenacher at the first corner at the Aragon Grand Prix. Four successive wins from Motegi onwards had moved Marquez into a 17-point lead over Terol with only one round to go. At Estoril, the race was red-flagged due to rain with Marquez running second to Terol. When returning to the grid for the second race, Marquez fell on the sighting lap and had to return to the pits. With repairs, Marquez started at the back of the field having not made it out of the pit lane before it closed five minutes prior to the start. Despite this, Marquez recovered to win the race and thus extend his lead before the Valencia finale. His tenth victory of the season moved him to within one of tying the record set by Rossi in 1997. He would fall short of tying it as he was fourth at the final race in Valencia to become the second-youngest World Champion after Loris Capirossi.

who did he work with?
Assen and Catalonia