In Christian sacred art, there are often paintings and drawings, where many saints are portrayed together. In this article, I present two photos, which actually show saints together.
The Ugandan martyrs

The Ugandan martyrs were a group of 22 Catholics and 23 Anglicans, who were killed by the order of King Mwanga in the local Kingdom of Buganda from 1885 to 1887. They were all men, most of them under the age of 30. The king got enraged that his courtiers, who converted to the faith, encouraged those courtiers, whom the king wanted to homosexually exploit, to resist his advances.
Saint Charles Lwanga (1861?–1886), is the most known of the group. He was one of the courtiers of the king, who converted to the Catholic faith and protected boys from the king’s homosexual advances. He also worked as a catechist. At first, the executioners burnt Saint Charles’ feet away slowly, while they told him that they would release him if he would renounce his faith, to which he replied: “You are burning me, but it is as if you are pouring water over my body.” He was then burnt alive, while he prayed.
The image was taken in October 1885, a few months before they died, at a mission station, where they welcomed the arrival of a new bishop. 20 of the martyrs can be seen on the image.
The 22 Catholic martyrs were beatified by Pope Benedict XV in 1920 and canonized by Pope Paul VI in 1964. Their feast day is on the 3rd of June.
Seven nuns martyred in China in 1900 (Shanxi martyrs)

Image taken from Wikimedia under the Public Domain license, here
Taiyuan is the capital of Shanxi province and has today 5 million residents. In 1899, seven nuns from the Franciscan Missionaries of Mary came to the city at the request of the local bishop, Saint Gregorio Maria Grassi (himself a martyr), to operate a hospital and organize education in an orphanage.
They were:
Saint Marie Adolphine (Anne-Catherine Dierks), 34 years old, from the Netherlands
Saint Marie de St. Just (Anne-Françoise Moreau), 34 years old, from France
Saint Maria Chiara (Clelia Nanetti), 28 years old, from Italy
Saint Marie Hermine de Jesus (Irma Grivot), 34 years old, from France
Saint Marie de Ste. Natalie (Jeanne-Marie Kuergin), 36 years old, from France
Saint Maria della Pace (Marianna Giuliani), 25 years old, from Italy
Saint Marie Amandine (Pauline Jeuris), 28 years old, from Belgium
They were martyred in the Taiyuan massacre during the Boxer Rebellion of 1900, when many foreign missionaries and Christians were killed, because they were seen as a foreign influence. The local governor sympathized with the rebels. The local bishop, his co-adjutor, and many priests, religious and lay people were brought to the house of a mandarin. A few days later, a mob of about 3000 Boxers, led by the governor, hacked them to death. The sisters were singing the Te Deum as they awaited martyrdom.
The sisters were all beatified by Pope Pius XII in 1946 and canonized by Pope John Paul II in 2000 as part of the group of the “120 Martyrs of China”. Their feast day is on the 8th of July and the feast of all the 120 Martyrs of China is on the 28th of September. https://catholicsaints.info/martyrs-of-shanxi/
Sources
Information about the Uganda martyrs on the website of the Uganda martyrs shrine
Article on the website of the Singapore and Malaysia province of the Franciscan Missionaries of Mary