From where did the tradition of erecting of three crosses around a church originate?

Apropos [Ken Graham's Question of 18th August](https://christianity.stackexchange.com/questions/96729/looking-for-sources-of-mediaeval-church-architecture-that-shows-and-or-explains) on medieval church architecture. One rarely comes across literature on the big crosses constructed around churches. For instance, you find an obelisk, a construction that traces its origin to Egyptian culture, at the centre of St Peter's Square, Rome. Of course, it has a cross on the top. Curious enough, the churches of Southern India, some of which trace their origin to the first century, have such peculiar constructions. St Thomas, the Apostle is believed to have reached India in 52 AD and established a few churches. The Portuguese who landed in 1498 rebuilt many such ancient churches, supplementing the local architecture with their own (See [Christianity in Kerala: Church Architecture](https://www.keralatourism.org/christianity/church-architecture/24)) . One particular feature is that of three crosses on a pedestal—erected on the south, north, and west of prominent churches, which almost invariably faced east. Some of these crosses, erected at a distance of say, half a mile, from the church, are accompanied by a small chapel locally called 'Kappela', the word tracing its root to the Portuguese language. These chapels would not host the Holy Eucharist and would be used for devotions like rosary and novena. Historians say that the construction of such an extension of the main church by way of crosses, was in vogue even before the arrival of the Portuguese since some of them have inscriptions in Syriac language. That would imply that the custom had originated with the Jews or any other people like the Chinese, Persians, and Arabs who had settled in India for trade. I am not aware if the tradition can be seen in the West. From where did the tradition of erecting three crosses around a church originate?