[1] During his long career, he was the most consistent and prolific practitioner of Impressionism's philosophy of expressing one's perceptions of nature, especially as applied to plein air (outdoor) landscape painting.

From 1883, Monet lived in Giverny, also in northern France, where he purchased a house and property and began a vast landscaping project, including a water-lily pond.

Monet's ambition to document the French countryside led to a method of painting the same scene many times so as to capture the changing of light and the passing of the seasons.

Frequently exhibited and successful during his lifetime, Monet's fame and popularity soared in the second half of the 20th century when he became one of the world's most famous painters and a source of inspiration for a burgeoning group of artists.

[19] Illness forced his return to Le Havre, where he bought out his remaining service and met Johan Barthold Jongkind, who together with Boudin was an important mentor to Monet.

[12] Upon his return to Paris, with the permission of his father, he divided his time between his childhood home and the countryside and enrolled in Charles Gleyre's studio, where he met Pierre-Auguste Renoir and Frédéric Bazille.

[16][A] While living in London, Monet met his old friend Pissarro and the American painter James Abbott McNeill Whistler, and befriended his first and primary art dealer, Paul Durand-Ruel, an encounter that would be decisive for his career.

[38] Monet and Camille were often in financial straits during this period—they were unable to pay their hotel bill during the summer of 1870 and likely lived on the outskirts of London as a result of insufficient funds.

[29][61] In an "unusually revealing" letter to Théodore Duret, Monet discussed his revitalised interest: "I am working like never before on a new endeavour figures in plein air, as I understand them.

[62] In the autumn of that year, they moved to the village of Vétheuil where they shared a house with the family of Ernest Hoschedé, a wealthy department store owner and patron of the arts who had commissioned four paintings from Monet.

[53] In December 1883 Claude Monet and Auguste Renoir left Paris by train for a short painting trip to Italy, along the Italian Riviera and to Genoa.

[73] Soon after his return to Giverny, Monet wrote to his art dealer Paul Durand-Ruel expressing his desire to go back to Italy and Bordighera for a longer stay.

[71] Monet initially intended to spend three weeks in the Ligurian town but ended up staying for a period of almost three months, from January 18 to April 5, during which he produced thirty-eight paintings with Bordighera motifs.

[81] Finally leaving Bordighera, Monet stopped in Menton to paint the Cap Martin and Monte Carlo before embarking on the 24 hour trip back to Giverny.

[15] In contrast to the last two decades of his career, Monet favoured working alone—and felt that he was always better when he did, having regularly "long[ed] for solitude, away from crowded tourist resorts and sophisticated urban settings".

Monet wrote daily instructions to his gardener, precise designs and layouts for plantings, and invoices for his floral purchases and his collection of botany books.

[97] Claude Roger-Marx noted in a review of Monet's successful 1909 exhibition of the first Water Lilies series that he had "reached the ultimate degree of abstraction and imagination joined to the real".

[101] The next year, Monet, encouraged by Clemenceau, made plans to construct a new, large studio that he could use to create a "decorative cycle of paintings devoted to the water garden".

To achieve his desired outcome, he began to label his tubes of paint, kept a strict order on his palette and wore a straw hat to negate glare.

[102] Monet's output decreased as he became withdrawn, although he did produce several panel paintings for the French Government, from 1914 to 1918 to great financial success and he would later create works for the state.

[103][101] During World War I, in which his younger son, Michel, served, Monet painted a Weeping Willow series as homage to the French fallen soldiers.

[15] Monet's portrayal of landscapes emphasised industrial elements such as railways and factories; his early seascapes featured brooding nature depicted with muted colours and local residents.

[24][98] The influence of his cataracts on his output has been a topic of discussion among academics; Lane et al. (1997) argues the occurrence of a deterioration from the late 1860s onwards led to a diminishing of sharp lines.

Helen Gardner writes: Monet, with a scientific precision, has given us an unparalleled and unexcelled record of the passing of time as seen in the movement of light over identical forms.

[34] These canvases were created with great difficulty: Monet spent a significant amount of time reworking them in order to find the perfect effects and impressions.

[50] Monet's home, garden, and water lily pond were bequeathed by Michel to the French Academy of Fine Arts (part of the Institut de France) in 1966.

Monet's Le Pont du chemin de fer à Argenteuil, an 1873 painting of a railway bridge spanning the Seine near Paris, was bought by an anonymous telephone bidder for a record $41.4 million at Christie's auction in New York on 6 May 2008.

[135] A few weeks later, Le bassin aux nymphéas (from the water lilies series) sold at Christie's 24 June 2008 auction in London[136] for £40,921,250 ($80,451,178), nearly doubling the record for the artist.

In October 2013, Monet's paintings L'Eglise de Vétheuil and Le Bassin aux Nympheas became subjects of a legal case in New York against New York-based Vilma Bautista, one-time aide to Imelda Marcos, wife of dictator Ferdinand Marcos,[138] after she sold Le Bassin aux Nympheas for $32 million to a Swiss buyer.

[138] Le Bassin aux Nympheas, also known as Japanese Footbridge over the Water-Lily Pond at Giverny, is part of Monet's famed Water Lilies series.