Who is Marta Ortega, the Zara heiress and most influential name in fashion you've never heard of?

Despite being the second richest man in the world, Zara founder Amancio Ortega usually keeps a low profile. But this weekend, the paparazzi caught the Spanish billionaire in a rare ‘display’ of mega-wealth in St Tropez, as boat watchers salivated over his £41.2 million super-yacht.

For the fashion crowd, though, there was something else on board to catch the eye - and, alas, it wasn’t 81 year-old Mr Ortega’s (inevitably Zara-bought) bathing suit. His 33 year-old daughter and the heiress to his empire, Marta Ortega, was also present, and flexing her impeccable taste for resortwear. The appearance has, consequently, given us a rare insight into the woman who is likely behind 20% of the contents in an average British woman’s wardrobe.           Marta acts as a senior creative consultant on all Zara Woman collections, and evidently has first pick of the new clothes before they hit stores. Despite her wealth (her father was worth £65 billion at last count) Ortega actually practices what she preaches, mixing her fully-stocked high street wardrobe with a few choice designer buys.

It’s thought that she’s the one, over her two siblings, who will take over the family business if her apparent-workaholic father ever retires, and she has been working her way up the ranks since beginning her career at the family firm as a shop girl in the Oxford Street store, during her Business Management studies in London.      With a circle of friends that includes Athena Onassis and Spain’s Queen Letizia (who is regularly spotted in Zara), Marta also is an established show-jumper, meaning that she’s a key figure in the Spanish equestrian social set. The entire family is, however, notoriously private, and great efforts have been made to keep her personal relationships out of the papers.

In 2012, Marta married fellow champion rider Sergio Alvarez Moya in a private ceremony on her father’s estate, with an altar designed by sculptor Anish Kapoor - forgoing a bargain Zara look for a Narciso Rodriguez couture gown, just this once. After splitting some months ago, she is now in a relationship with Carlos Torretta, a model agent who establishes deals for Kendall Jenner and Adriana Lima in Europe. Torretta is the son of Roberto Torretta, the Argentinian designer and vice president of ACME , the Association of Fashion Creators of Spain and Carmen Echevarría, a woman who counts Jane Birkin among the clients at her Madrid boutique, meaning that this new relationship would only serve to seal the credentials of the first family of Spanish fashion.      As she continues to rise at the company, and is establishing herself among the new Madrid fashion set, Marta Ortega is definitely a name worth watching. In fact, considering the fact that Zara's sales hit £535.2 million in the UK alone last year, she may already be the most influential name in fashion that you’d never heard of.