| Year | Detail |
| 1851 |
Ahlstrom was founded, and timber trading, shipping, and sawmill operations started to grow in Noormarkku, Finland. |
| 1963 |
Ahlstrom acquired Cartiere Giacomo Bosso S.p.A., an Italian paper company, marking a significant international expansion and establishing Ahlstrom as a pioneer among major Finnish companies in global operations. This acquisition helped Ahlstrom grow internationally by acquiring a paper mill in Mathi, Italy, that produced filter papers and rifle cartridge paper. |
| 2017 |
Ahlstrom Corp. and Munksjö Oyj merged to form Ahlstrom-Munksjö, creating a global leader in sustainable and innovative fiber-based solutions. |
| 2018 |
Ahlstrom-Munksjö acquired MD Papéis’ Caieiras specialty paper mill in Brazil for a debt-free purchase price of around $115.7 million. This acquisition significantly strengthens Ahlstrom-Munksjö’s offering in South America and provides further growth opportunities. |
| 2022 |
Ahlstrom-Munksjö Holding 3 Oy completed the ownership arrangement of its Decor business according to the plan announced. Currently, Ahlstrom-Munksjö has started operating under the business name Ahlstrom. |