After Paul Signac’s visit to Constantinople in 1907, the following February he travelled to Italy, where he toured Florence, Rome and other cities before returning to Venice in late March. He remained there for two months before going back to Saint-Tropez via Verona. In November, he cruised the coast from Antibes to Nice.

He painted Venice. Customs House in 1908, following his return to the city. This reverses his previous compositions by placing the Customs House in the mid-ground, with masts and sails behind. This loses the depth and grandeur of those earlier works.
In April 1909, Signac visited London briefly, where he sketched some Turners in the National Gallery, and met Lucien Pissarro and Walter Sickert.

Signac’s Avignon, Evening (The Papal Palace) from 1909 is one of several works that year showing grand architecture from the water. Critical reception was disappointingly mixed, though.
This palace is one of the largest mediaeval Gothic buildings in Europe, and was constructed from 1252 onwards. From 1309, it became the residence of the Popes, starting with Clement V who was unable to face the violence taking place in Rome. Nearly seventy years later, the Pope left Avignon and returned to Rome, only for antipopes to reside here until 1403. The buildings then steadily fell into decay until restoration started in 1906, when it became a national museum.
At the end of 1909, Signac went to what is now Ukraine for a travelling International Exhibition, which started off in Odessa on the coast of the Black Sea, then made its way to Kyiv, Saint Petersburg in Russia, and Riga in Latvia. He exhibited three of his paintings there.
The following year, his production of oil paintings fell markedly, and he devoted more of his time to watercolours, which I will consider later in this series. This was in part the result of the final illness of his friend Henri-Edmond Cross, who died that May, and of Signac’s deepening relationship with Jeanne Selmersheim-Desgrange, a Neo-Impressionist artist who was married to an architect.
In November 1910 to January 1911, three of Signac’s oil paintings were exhibited at the exhibition of Post-Impressionist paintings at the Grafton Galleries in London, organised by Roger Fry. This was largely responsible for the surge in interest in Britain, and the formation of artist-organised groups like the Camden Town Group.
In late 1911, Signac was made a chevalier of the Legion of Honour, but his mother became ill and died when visiting Saint-Tropez.

La Rochelle, Leaving the Harbour is one of only four oil paintings made by Signac in 1912, and was based on a series of watercolour studies he made of the port from 1911 onwards. These feature the departure of the tuna fishing fleet in June. The round tower on the left is the Tour de la Chaîne, built in 1375, and the castellated tower on the right is the Tour Saint-Nicholas from 1384. Signac apparently found this view difficult to paint, and jokingly blamed Corot for his trouble.
In February-March 1913, fifteen of Signac’s watercolours and one oil painting were exhibited in the International Exhibition of Modern Art held in New York, better-known as the Armory Show, which brought revolution to the art world of North America.
That year, he painted five oil paintings. He also separated from his wife, although they never divorced, and he moved into a rented villa at Cap d’Antibes with Jeanne Selmersheim-Desgrange, who was expecting their first child.
The First World War broke out while Signac was holidaying with his partner and their young daughter in the mountains. They returned to Antibes at the beginning of October.

Just as Signac had painted exhaustive views around Saint-Tropez while he lived there, his move to Antibes brought a new coast to inspire him. He appears to have painted this wonderful dusk view of Antibes, Evening at the outbreak of war in 1914, before he became too depressed to paint. It reiterates his influence by Horace Vernet.
During the war years, Signac remained depressed, and struggled to paint much. In April 1915, he was officially made a war artist for the French Navy, but his bouts of asthma prevented him from travelling overseas to take advantage of opportunities to paint more exotic ports.

Signac painted this view of The Port of La Rochelle in 1915, showing the reverse of Leaving the Harbour above.

Signac’s most remarkable painting of the war years is The Pink Cloud, Antibes, from 1916. Sadly, this image doesn’t do it any favours, but is the best available.
As with most of his oil paintings, this had its origins in watercolour sketches, in this case made during 1914. At the end of that year, he started his first version in oils, then decided that the canvas was too small, and transferred it to a larger one. Signac referred to the cloud as a ‘cauliflower’, and envisaged dancing figures in the rising arcs of cloud at the upper left, together with a procession of warships on its horizon. He didn’t complete it until 1916.
My last two paintings show another view of the harbour at Antibes, similar to that in Antibes, Evening above.

Antibes. Petit Port de Bacon exists in two versions, both painted in 1917. That above, which should correspond with Cachin 515, is in a private collection, and that below (Cachin 516) in Helsinki’s Ateneum. However, the images of them in Cachin appear to have been transposed.

Signac didn’t really return to oil painting until the end of the war.
References
Cachin F (2000) Signac. Catalogue raisoné de l’Oeuvre Peint, Gallimard. ISBN 2 07 011597 6.
Ferretti-Bocquillon M et al (2001) Signac 1863-1935, Yale UP. ISBN 0 300 08860 4.
Ferretti-Bocquillon M et al. (2013) Signac, les Couleurs de l’Eau, Gallimard. ISBN 978 2 07 014106 7.