･1880An office for the head of each village (mura) in Abuta-gun was established in Abuta-mura. These managed Abuta-mura, Furenai-mura, Benbe-mura, Rebun-mura.
･1882Abuta-mura merged with Furenai-mura.
･1893Kutchan-mura (the present Kutchan-cho and Kyogoku-cho) spun off from Abuta-mura.
･1897Makkari-mura (the present Makkari-mura, Rusutsu-mura, Niseko-cho, and Kimobetsu-cho) spun off from Abuta-mura.
･1909Benbe-mura (the present Toyoura-cho) spun off from Abuta-mura, and the Abuta-mura Village Office was established.
･April 1, 1938 The primary municipal organization came into effect.
･October 1, 1938 The municipal organization came into effect, and Abuta-mura became Abuta-cho.
[Former Toya Village]
･1887Seventy-six people relocated from Kagawa prefecture to the Ohara region.
･1895Several tens of households of tenant farmers moved to 600 hectors in Naruka and started developing the land, which become the foundation of the present Toya-mura.
･1902The Abuta-mura and Benbe-mura Union Office was established. The primary municipal organization came into effect.
･May 5, 1920Toya-mura was founded through a spin off from Abuta-mura.
･1938Toya-mura was awarded the Interior Minister's Award as an excellent local government.
･1947Elections were held for the village assembly, giving birth to the first publicly elected the head of the village.
･March 27, 2006Toyako-cho was created through the merger of Toya-mura and Abuta-cho, bringing an end to Toya-mura.
･March 27, 2006Toyako-cho was newly established through the merger of Abuta-cho and Toya-mura. Originally, they were a unified village (Abuta-mura; equivalent to the former Abuta-cho). However, in 1920 Toya-mura spun off from Abuta-mura. The two towns merged for the first time in 86 years.
･April 23, 2007Toyako-cho was chosen to host the 2008 G8 Summit.
・In July 1663, the volcano erupted, creating Ko-Usu (Small Usu) and burning or burying neighboring houses. Five people died.
・In December 1769, the volcano erupted, there were pyroclastic flows (fast-moving currents of hot gas, ash, and rock), and residential homes were burnt down.
・In March 1822, on the fourth day following an increase in seismic activity, the volcano erupted. Later, there were pyroclastic flows, and a complete village was destroyed. A total of 103 died or went missing.
・In April 1853, ten days after seismic activity increased, the volcano erupted. The eruptions continue for several months. During that time, there were pyroclastic flows, and the lava dome Dai-Usu (Large Usu) was created.
・Starting on July 19, 1910, there were a series of earthquakes, and on July 25 there was an explosion.
Mud and rocks were spewed from around 45 explosion craters, and there was a flood of mud. Houses, forests, and agricultural land were damaged. One person died from the mud flood.
・Starting in the last part of December 1943, there were a series of earthquakes, and on June 23, 1944, the volcano erupted. In the first part of July, there was a major eruption of stones and volcanic ash, and throughout October, volcanic ash clouds spewed repeatedly. Bulges in the ground persisted into 1945, and this was later referred to as Showa Shinsan (Showa New Mountain). One person died.
・On August 6, 1977, discernable earthquakes start occurring, and on the following day, August 7, there was an eruption of light rocks.
Numerous eruptions occurred through August 14, including four major ones. In July 1978, there was an explosion of magma steam, and in October, a mud slide occurred, killing 3 people.
・On March 31, 2000, there was an explosion at the foot of the Mount Nishi. The following day, Mount Konpira erupted, and 97% of all residents of the town (excluding the Shimizu and Hanawa areas) took refuge outside the town.