This is very self explanatory. You just post a history of your nation, and you can look at other nations history. For example, this is my nations history:
1860- Italy is formed, but The Papal State and Venetia remain beyond it's control.
1866- Austro-Prussian War, Italy joins Prussia and receives Venetia.
1870- Franco-Prussian War, France withdraws it's troops from Rome, and Italy occupies The Papal State. Italy is fully united.
1882- Italy joins The Triple Alliance with the German Empire and Austria-Hungary.
1884- Italy gains it's first official colony, Italian Somaliland.
1890- Italy gets another colony, Eritrea.
1912- Italy gains a third colony in Africa, Libya.
1918- Beginning of The Italo-Siamese War, Italy occupies Southern Siam.
1919- As Italian troops approach Bangkok, Siamese troops evacuate the city and then burn it, hoping to stall the Italians.
1920- Italy continues to push into Siam, with Germany sending troops and supplies from Kaiser Wilhelms Land in support of Italy.
1921- Siam surrenders, and Italy gains it's fourth colony, Italian Indochina. The Italians build another city on the ruins of Bangkok, dubbing it New Bangkok. As Germany helped Italy, Italy's bonds with The Triple Alliance are strengthened.
1926- The alliance between Great Britain and Belgium turns sour and breaks up, and The Netherlands declares war on Belgium to unite the former Netherlands. The Triple Alliance declares it's intentions to support The Netherlands, and France quickly takes back it's support of Belgium, not wanting to risk war against 3 nations.
1929- The Netherlands wins The Dutch War against Belgium and Luxembourg, and renames itself The United Kindom of Greater Holland. Belgian Congo becomes Dutch Congo. The UKGH, as a way of saying thanks, joins The Triple Alliance, which becomes The Quad Alliance.
1932- The Ottoman Empire joins The Quad Alliance, which becomes The Central Alliance.
1937- Beginning of The War Of Scandinavia, fighting breaks out between The Dual Alliance of Denmark and Norway, and The East Scandinavian Alliance of Sweden and Finland(Independent 1934). Germany, having a border with Denmark, sends a warning message to all nations involved: attack any Central Alliance member, and face war.
1938- Sweden invades Denmark, Finland invades Norway, and Danish Artillery fires into German Territory. The Central Alliance declares war on Denmark and Norway, who are allied with France, Spain, and Portugal. A Pan-European War erupts between The Central Alliance of Germany, Austria-Hungary, Italy, The Ottomans, Greater Holland, Sweden, and Finland and The West European Union of France, Spain, Portugal, Norway, and Denmark.
1943- Pan-Euro War ends, West European Union is defeated. Germany annexes Denmark and France cedes French Morocco to Germany. Austria-Hungary, looking eagerly for African colonies, receives Portuguese Guinea and Río Muni, small colonies, but Austria-Hungary's first. Finland gains part of Northern Norway and a colony, French Indochina. Italy regains Nice and Savoy from France. The Ottomans retake Tunisia. Sweden takes the rest of Norway, as well as Iceland and Senegal from France. France falls into revolution and Spain decides to join The Central Alliance.
1944- Now. The Central Alliance, the leading power in the world, consists of: Italy, Germany, Austria-Hungary, Greater Holland, The Ottoman Empire, Sweden, Finland, and Spain. The Great Alliance, formed to challenge The Central Alliance, consists of: America, China, Mexico, Brazil, Japan, and Portugal.