川原慶賀（田口種美・登与助とも）は、1786年（天明6）頃の生まれ。父は絵師の川原香山で唐絵目利の石崎融思とかなり親密な間柄であったことが知られている。1811年（文化8）の頃には出島に自由に出入りできる「出島出入絵師」となり、出島商館長ブロンホフや商館員フィッセル、商館医シーボルトの求めに応じて日本の文物を描いている。
　商館員たちの求めに応じて何でも描ける優秀な絵師川原慶賀ではあったが、シーボルトは植物研究のための標本デッサンを正確に描くためどうしても西洋画法に精通した絵師が必要であった。そのためヴァタビア総督に画家の派遣を要請している。この要請に応えて1825年（文政8）来日したのが薬剤師のビュルガーと専門の画家ではないものの絵心のあったデ・フィレニューフェであった。慶賀は、このデ・フィレニューフェから西洋画法の手ほどきを受けることとなる。
　1826年の江戸参府においてシーボルトは、慶賀を同行させている。慶賀はシーボルトの要望や指示に従い、街道の様子や名勝、神社仏閣、京・大坂・江戸の様子、公家・武家の装束、旅の道中で観察される動・植物、風俗までありとあらゆる文物を描いた。
　この江戸参府の際、シーボルトが友好を深めた最上徳内、高橋景保らの好意が後のシーボルト事件に発展してゆく。1829年（文政11年12月）、シーボルトが御禁制の地図や葵の紋付服などを国外に持ち出そうとしたことが発覚し国外追放となる「シーボルト事件」により、慶賀も連座して入牢、「叱り」という処分を受ける。その後出島出入絵師としての仕事は復活したようであるが、1842年（天保13）長崎港の風景を描いた際、警備船の幕に細川家と鍋島家の紋まで書き込んだため、長崎所払いの処分を受けている。
　ところがその4年後の1846年（弘化3）、長崎の飛鳥氏らが先祖菩提のため石崎融思一門に依頼し描かせた長崎市脇岬観音寺の天井画150枚の中の5枚に慶賀の落款が存在する。石崎融思と慶賀との関係が推測できる。1860年（万延元）に慶賀が75歳の作品であることを示す年記を持つ「永島きく刀自像」により慶賀の生年はほぼ推定されているが、残念ながら没年およびその墓所は不明である。

Keiga Kawahara (Tanemi Taguchi or Toyosuke) was born in 1786. His father, Kozan Kawahara is thought to have had a considerably close relationship with Yushi Ishizaki, who was a kara-e mekiki, or an official art inspector of Chinese imports. Around 1811, Keiga Kawahara was appointed as a painter for Dejima Factory, an artist who is allowed access to Dejima, where he depicted things Japanese in response to requests from Blomhoff (director of the Dutch East India Company Dejima Factory), Fisscher (a Dutch East Indian Company employee), and Siebold (a physician at the Dutch East India Company Dejima Factory).
Although Keiga Kawahara was an excellent painter who could draw anything required by the Dutch residents of Dejima, Siebold absolutely needed artists with a mastery of Western painting techniques, to draw precise sketches of specimens to pursue his botanical studies. As such, Siebold required the governor-general at Batavia to dispatch such painters. Responding to his request, in 1825 two persons were sent to Japan: one was Heinrich Burger, a pharmacist, and the other was de Villeneuve, who was not an expert painter but had an aptitude for painting. Keiga was then taught the basics of Western painting techniques by de Villeneuve.
When making the court journey to Edo in 1826, Siebold took Keiga with him. In compliance with Siebold's requests and instructions, Keiga drew a variety of objects, including street scenes, scenic spots, shrines and temples, circumstances of Kyoto, Osaka and Edo, court noble and samurai attire, and plants and animals as well as folk they observed on their journey to Edo.
During his stay in Edo, Siebold deepened friendships with Tokunai Mogami and Kageyasu Takahashi, whose kindness subsequently led to the so-called Siebold Incident: In 1829, Siebold was expelled from Japan, since it was revealed that he attempted to take out of the country detailed maps of Japan, a kimono with the hollyhock crest of the Tokugawa family and other banned items. It was an act strictly forbidden by the Tokugawa shogunate. Owing to the engagement in the Siebold Incident, Keiga Kawahara was also put in prison and reprimanded. After his punishment, he is thought to have resumed his work as a painter for Dejima Factory. However, in 1842, when Keiga painted a landscape of Nagasaki Port, he depicted the crests of the Hosokawa and Nabeshima families on the patrol vessel screens. He was punished yet again and dismissed from Nagasaki.
Nevertheless, we can find Keiga's signature and seal on five of 150 ceiling paintings in Nagasaki, drawn by Yushi Ishizaki and his pupils in 1846, i.e., four years after Keiga's dismissal. These paintings were drawn on the ceilings of Wakimisaki Kannon Temple, Nagasaki City, at request of Asuka clan and other clients in Nagasaki for the repose of their ancestors. This implies the close relationship between Yushi Ishizaki and Keiga. Since the portrait of Madame Kiku Nagashima, painted in 1860, has a record indicating that it was Keiga's work at the age of 75, we can presume the year of his birth. Unfortunately, however, the year of his death and the location of his grave are unknown.