The crusaders mobilize an army of perhaps…

The short Russian prose ballad, “The Tale of Igor's Campaign”, composed in 1187, vividly describes a military episode of the period.

The poem gives an account of a failed raid of Igor Svyatoslavich (d. 1202) against the Polovtsians, or Cumans, of the Don River region.

While some have disputed the authenticity of the poem, the current scholarly consensus is that the poem is authentic and dates to the medieval period (late twelfth century).

Sigtuna is attacked by Curonian and Oeselian raiders in 1187.

According to the archaeologist Sten Tesch, excavations have not verified the traditions of destruction of the town.

In response, …

…King Canute I of Sweden builds a castle on the island of Stockholm in 1187, one of many such fortifications made necessary by heathen incursions from the Baltic lands.

Saxo Grammaticus renders some Latinized versions of poetry from the Viking era in his Gesta Danorum (Deeds of the Danes), which records the history of Denmark up to 1186 and includes the earliest version of the Hamlet story.

Radom, a city in central Poland about ninety kilometers (fifty-five miles) south of Warsaw, is first mentioned in 1187.

Isaac fails to crush the revolt of the Bulgarians and Vlachs, even though he leads expeditions against them in 1186-87.

The Asen brothers regroup, obtain the support of the Cumans, and launch a series of devastating raids against the empire in Thrace and Macedonia.

The brothers check the imperial army in Thrace in 1187; and, in the armistice that follows, which forces Constantinople’s recognition of an autonomous Bulgarian state, …

…their younger brother Kaloyan is sent as hostage to Constantinople.

He escapes, however, and war with Bulgaria breaks out, to continue intermittently.

In other developments, Constantinople patches things up with Venice in 1187.

Muhammad takes the whole of Punjab in 1187, thus completing the Ghurid conquest of the Ghaznavid empire in India and driving the Ghaznavids east into the Bihar and Bengal regions.

The Bulgarian church after the collapse of the first Bulgarian state had fallen under the domination of Greek ecclesiastics who have taken control of the see of Ohrid and attempted to replace the Bulgarian Slavic liturgy with liturgy in the Greek language.

Bulgarian culture is by this time too deeply rooted to be easily removed, and Constantinople, beset by the attacks of the Seljuq Turks and the disturbances of the crusaders, lacks the power to support a more forcible Hellenization.

Raymond of Tripoli has allied with the Muslim sultan Saladin against Guy.

Guy, hoping to establish a truce  in April 1187 sends an embassy to Raymond, led by Balian of Ibelin, Gerard de Ridefort, master of the Knights Templar; Roger des Moulins, master of the Knights Hospitaller; Reginald of Sidon, and Archbishop Joscius.