Ryōmō Line

The line has two distinct origins. The Oyama–Maebashi section was built by a private company, the Ryōmō Railway (両毛鉄道), specifically to move the region's raw silk and silk cloth to market; the short Maebashi–Shin-Maebashi section was instead built by Nippon Railway as an extension of what is today the Takasaki Line. Nippon Railway reached the area first, opening the line from Takasaki to the original Maebashi station on 20 August 1884; that first Maebashi stop stood on the right bank of the Tone River, away from the present site.

The Ryōmō Railway then built east-to-west from Oyama. It opened Oyama to Ashikaga on 22 May 1888, bringing Tochigi, Sano and Ashikaga stations into service, and extended on to Kiryū on 15 November the same year. On 20 November 1889 the final stretch from Kiryū to Maebashi opened, completing the company's line and adding Ōmama (the first station of that name, today's Iwajuku), Kunisada, Isesaki and Komagata. Maebashi station had by then moved across to the left bank of the Tone, and on 26 December 1889 Nippon Railway extended over the river into the Ryōmō Railway's Maebashi station, linking the two railways; the old Maebashi stop was closed. This shared history is why the Shin-Maebashi–Maebashi section still operates almost as one with the Takasaki Line today.

Consolidation followed quickly. Nippon Railway absorbed the Ryōmō Railway, the Oyama–Maebashi section passing to it on 1 January 1897. Less than a decade later Nippon Railway itself was nationalised, on 1 November 1906 under the Railway Nationalization Act, bringing the whole route into state hands. When the government drew up its formal list of line names on 12 October 1909, the Oyama–Takasaki section was unified under the name "Ryōmō Line."

The line's western end was then reshaped by the building of the Jōetsu Line. Shin-Maebashi station opened on 1 July 1921 together with the Jōetsu South Line, and when the Jōetsu Line was completed through to the north on 1 September 1931, the Shin-Maebashi–Takasaki section became track shared between the two lines. That overlap lasted until 1957: on 27 November of that year the Maebashi–Shin-Maebashi section was electrified, and on 20 December the Ryōmō Line's western terminus was moved back from Takasaki to Shin-Maebashi — shortening the line by 7.3 km and ending the duplication with the Jōetsu Line.

Motive power modernised in stages. Diesel railcar operation began on the Kiryū–Takasaki section as early as 10 July 1934, and many small intermediate stations were added in the post-war years to serve local passengers. Electrification reached the line in pieces — the Takasaki–Shin-Maebashi end was wired in 1947 and the Maebashi–Shin-Maebashi link in 1957 — and was finally completed across the whole route on 1 September 1968, when the Oyama–Maebashi section was electrified; around the same time many of the lightly used halts opened in the 1950s were suspended, and the line was largely converted to centralised traffic control.

With the break-up and privatisation of Japanese National Railways on 1 April 1987, the entire Ryōmō Line passed to JR East as the Type 1 railway operator, with Japan Freight Railway (JR Freight) holding Type 2 freight-operating rights over the whole line. Freight working did not last: scheduled freight trains ceased and JR Freight's Type 2 rights were withdrawn on 1 April 2004, leaving the line entirely given over to passenger traffic. Line-wide ATS-P safety equipment was completed on 11 October 2009.

In recent years the line has remained a busy regional artery linking the textile towns of the Ryōmō district, with the Maebashi–Shin-Maebashi end drawn into the wider Tokyo network through Ueno–Tokyo Line and Shōnan–Shinjuku Line through services. A new station, Ashikaga Flower Park, opened on 1 April 2018. In October 2019 the line suffered serious damage when Typhoon Hagibis undermined the abutment of the Nagano River bridge between Ōhirashita and Tochigi, suspending the Oyama–Kiryū section; service was progressively restored and the whole line reopened on 11 November 2019. The withdrawal of the "Akagi" and "Swallow Akagi" limited expresses from the Maebashi–Shin-Maebashi section on 13 March 2021 ended the last regular limited-express working on the line, which is now served overwhelmingly by local trains.

• 188420 August: Nippon Railway opens the Takasaki–Maebashi (original) section, an extension of today's Takasaki Line; the first Maebashi station stands on the right bank of the Tone River.
• 188822 May: the private Ryōmō Railway opens Oyama–Ashikaga, with Tochigi, Sano and Ashikaga stations; on 15 November it extends Ashikaga–Kiryū, opening Kiryū station.
• 188920 November: Kiryū–Maebashi opens, completing the Ryōmō Railway's line (Ōmama [now Iwajuku], Kunisada, Isesaki and Komagata stations open); on 26 December Nippon Railway crosses the Tone into the Ryōmō Railway's Maebashi station, linking the two railways, and the old Maebashi station closes.
• 18971 January: the Oyama–Maebashi (Ryōmō Railway) section is transferred to Nippon Railway, which had absorbed the company.
• 19061 November: Nippon Railway is nationalised under the Railway Nationalization Act; the whole route passes into state hands.
• 190912 October: under the government's official list of line names, the Oyama–Takasaki section is named the 'Ryōmō Line'.
• 19211 July: Shin-Maebashi station opens together with the Jōetsu South Line (Shin-Maebashi–Shibukawa).
• 19311 September: with the full opening of the Jōetsu Line, the Shin-Maebashi–Takasaki section becomes track shared with (duplicated by) the Jōetsu Line.
• 193410 July: diesel railcar operation begins on the Kiryū–Takasaki section.
• 19471 April: the Takasaki–Shin-Maebashi section (continuing toward Minakami) is electrified.
• 195727 November: the Maebashi–Shin-Maebashi section is electrified. 20 December: the Ryōmō Line's western terminus is moved from Takasaki back to Shin-Maebashi (−7.3 km), ending the duplication with the Jōetsu Line.
• 19681 September: the Oyama–Maebashi section is electrified, completing electrification of the whole line; many lightly used 1950s halts are suspended around this time.
• 19871 April: with the break-up and privatisation of JNR, the entire line passes to JR East as Type 1 operator, with JR Freight as the Type 2 freight operator over the whole line.
• 20041 April: scheduled freight operation over the whole line is abolished and JR Freight's Type 2 rights are withdrawn.
• 200911 October: ATS-P safety equipment is completed across the whole line.
• 20181 April: Ashikaga Flower Park station opens.
• 201913 October: Typhoon Hagibis undermines the abutment of the Nagano River bridge between Ōhirashita and Tochigi, suspending the Oyama–Kiryū section; the whole line is restored on 11 November.
• 202113 March: the 'Akagi' and 'Swallow Akagi' limited expresses are withdrawn from the Maebashi–Shin-Maebashi section, ending the last regular limited-express working on the line.