He is believed to have passed away in 1577, and it is unclear as to how El Greco went about producing an accurate portrait of him some two decades later. Diego is known to have been local to Toledo, and so would have been familiar with the artist, though El Greco himself only moved to Spain in the year of his death. The artist would therefore have to have needed help from others in order to produce this piece. Most likely, there would have been drawings or even paintings of Diego whilst he was alive which El Greco then worked from in order to get an understanding for the physical characteristics of his subject. Normally the artist worked from religious figures who lived many centuries previous, but had an accepted appearance within that, or with local Toledo residents who could physically sit for him. The piece that he delivered in circa 1600 is only around 68cm by 57cm and currently is at the El Greco Museum in Toledo. The artist found much inspiration from his time here and featured the region's landscape across the background of many paintings whilst living here.

The format of this painting follows the same technique used for many living artists - we find the subject from waist up, in his traditional clothing. Behind him is a dark brown tone which avoids any distractions and also helps to bring out the vivid white tones on the clothing. The figure looks directly at us, with an entirely neutral expression. His beard is short but tidy, greying at the edges. His hair is likewise, though mainly covered by his hat. He is presented as an ageing man, which is perhaps how people remembered him at the time. The trademark extended, prominent nose is present, and this was how El Greco regularly depicted people within his portraits. The folds of his garment is beautifully delivered and whilst not being one of his most famous paintings, this portrait of Diego de Covarrubias y Leyva is still an important addition to his considerable oeuvre. It remains within the El Greco Museum where his reputation and achievements continue to be taught to new generations.

El Greco held strong relationships with many religious figures and they would regularly seek his assistance on a variety of projects. His strong faith in God helped him to gain their trust, and over time they would get used to his expressive and slightly unusual artistic approach. Word of mouth played a strong role in promoting his career and he also took on assistants in order to avoid rejecting any commissions once his workload started to increase. He remains the most famous Greek artist of all time, though his impact went far beyond the boundaries of Crete, spreading all across Europe thanks to his desire to seek out new challenges abroad. His popularity remains just as strong today and few artists have gone to Spain from abroad and had quite the impact as El Greco would do.

Portrait of Diego de Covarrubias y Leyva in Detail El Greco