Would tying sulphur to the feet of birds allow you to burn down a house?

Question

According to legend:

The last vengeance took place in the year 946 when Olga traveled around the land of the Drevlyans in order to gather tributes. She besieged the town of Iskorosten, which refused to pay her. According to legend, the Princess asked that each household present her with a dove as a gift. Then she tied burning papers to the legs of the doves and let them fly back to their homes. As a result, the entire town was destroyed by fire.

Wikipedia has the same story, but with sulphur.

The Drevlians begged for mercy and offered to pay for their freedom with honey and furs. She asked for three pigeons and three sparrows from each house, since she did not want to burden the villagers any further after the siege. They were happy to comply with such a reasonable request. Now Olga gave to each soldier in her army a pigeon or a sparrow, and ordered them to attach by thread to each pigeon and sparrow a piece of sulfur bound with small pieces of cloth. When night fell, Olga bade her soldiers release the pigeons and the sparrows. So the birds flew to their nests, the pigeons to the cotes, and the sparrows under the eaves. The dove-cotes, the coops, the porches, and the haymows were set on fire. There was not a house that was not consumed, and it was impossible to extinguish the flames, because all the houses caught on fire at once.

Clearly, this is exaggerated. However, is it a feasible method of burning down a house and is there any evidence that this event actually occurred?

Answer 1

Russian Wikipedia says

после безуспешной осады в течение лета Ольга сожгла город с помощью птиц, к ногам которых велела привязать зажжённую паклю с серой.

Which means that pieces of cloth (which is not cloth actually) were set on fire.

But my first idea was that sulphur could create fire because of friction, like when birds fly or land in the nest pieces of suplhur rub against each other and produce flame.

EDIT: I have found a part in Primary Chronicle (http://en.wikipedia.org/wiki/Primary_Chronicle) about the vengeance of Olga and it says that every bird had a tinder tied to its leg.

Here is a quote:

Древляне же с радостью вошли в город и поведали обо всем людям, и обрадовались люди в городе. Ольга же, раздав воинам - кому по голубю, кому по воробью, приказала привязывать каждому голубю и воробью трут, завертывая его в небольшие платочки и прикрепляя ниткой к каждому. И, когда стало смеркаться, приказала Ольга своим воинам пустить голубей и воробьев. Голуби же и воробьи полетели в свои гнезда: голуби в голубятни, а воробьи под стрехи, и так загорелись - где голубятни, где клети, где сараи и сеновалы, и не было двора, где бы не горело, и нельзя было гасить, так как сразу загорелись все дворы.

Finally I have found an english translation of this chapter. It starts in the year of 6454 (946), paragraph 7 (by the way there is typo - year 8454 instead of 6454):

Now Olga gave to each soldier in her army a pigeon or a sparrow, and ordered them to attach by a thread to each pigeon and sparrow a match bound with small pieces of cloth. When night fell, Olga bade her soldiers release the pigeons and the sparrows. So the birds few to their nests, the pigeons to the cotes, and the sparrows under the eaves. Thus the dovecotes, the coops, the porches, and the haymows were set on fire. There was not a house that was not consumed, and it was impossible to extinguish the flames, because all the houses caught fire at once. The people fled from the city, and Olga ordered her soldiers to catch them. Thus she took the city and burned it, and captured the elders of the city. Some of the other captives she killed, while she gave others as slaves to her followers. The remnant she left to pay tribute.

So this is only a mistake in english version of text in wikipedia and Rory Alsop was right with the idea of birds carrying ember.

Answer 2

Houses burning down from flying embers is a very real event, and there is evidence from various eras of vast sections of cities burning down due to a fire in one building - as they didn't have fire safety codes back then.

So the question really is about whether a bird with a burning package tied to its leg (out of a flock of similarly burdened birds) will land on a house (or possibly fly over a house, and the burning package drop from its leg onto a flammable roof)

Panic behaviour in different types of birds varies, but most tend to flocking and some will return to their nests, so this combination could give good reason to believe that the birds (which came from the town) would fly homewards with the burning embers attached.

I can't find any information on whether birds with fire attached will flock together or will spread apart (needs a study?) but flocking to a small area can be destructive enough without fire.

Update from Chad's comment - Sulfur in itself will not spontaneously combust, so if the packages were just sulfur but not burning, this seems incredibly unlikely, despite sulfur being very easy to light.