The Land Alienation Act of 1900. The colony agitation and Pagri Sambhal Jatta in 1907. The Ghadar Party in 1913 and the failed rising of 1915. Half of India's soldiers in the First World War. The Rowlatt Act and Jallianwala Bagh in 1919.
The Gurdwara Reform Movement from 1920: Nankana Sahib, the keys, Guru ka Bagh, Jaito, and the Sikh Gurdwaras Act of 1925. The Babbar Akalis. Bhagat Singh hanged in 1931. The Unionist Party governs.
1947. The province is cut in two, ten to twelve million people move, somewhere between two hundred thousand and a million die, and no state has counted either figure.
PEPSU and the muzara movement. The Punjabi Suba campaign and the reorganisation of 1966. Bhakra. The Green Revolution from 1966. Emigration to Britain and Canada.
1978, 1984, and a decade of militancy and counter-insurgency in which around twenty thousand people die.
The century ends with a state that has fed India, lost half its territory twice, and cannot pay its bills.
The century begins with the canal colonies and the first mass peasant agitation, runs through Ghadar, the Akali morchas, the war recruitment and Partition, and reaches 1966 with the state redrawn by language.
The second half is the Green Revolution, the water, the accord, the decade of violence, and the emigration that has been going on the whole time and accelerated at the end of it.
No single book covers it. Every part of it has its own literature and its own partisans, and a person wanting the shape of the whole century has to assemble it themselves.