Ichinomiya (一宮)

"Ichinomiya" (lit. first shrine) may refer to

The highest ranking Shinto shrine in each of the old provinces of Japan before Edo period. This is described in this section.

The first son born to the Emperor of Japan.
The first born prince is also referred to as 'Ichi-no-Miko.'
The first born princess is referred to as 'Onna Ichinomiya.'

Explanation
Ichinomiya (lit. first shrine) is the highest ranking Shinto shrine within a given area. The 'no' of "Ichinomiya" may be written using hiagana or kanji. The term 'Ichinomiya' ordinarily refers to highest ranking Shinto shrine in each of the old provinces of Japan.

The expression is thought to have derived from the first temple visited by a provincial governor on the pilgrimage made when he was assigned to a province. However, it is not a term defined in writing but rather one that arose organically according to the history and type of shrine.
The second shrine visited by a provincial governor during his pilgrimage was referred to as 'ninomiya' and the third as 'sannomiya.'
Even after the collapse of the ritsuryo system, the top ranking shrine in an area continued to be referred to ichinomiya. The designation was originally applied according to various factors such as the type of shrine but over time the ichinomiya shrine of an area may have been relocated and numerous other shrines would compete for the title.
Nowadays all shrines are considered to be equal but in the past most of the shrines denoted ichinomiya were named 'XX Province Ichinomiya.'

There are many cases in which the area around an ichinomiya shrine became named 'Ichinomiya.'

All of the shrines considered to be ichinomiya formed the 'Zenkoku Ichinomiya kai' (although not all ichinomiya shrines joined).

The early Edo period Shinto follower Mitsuyoshi TACHIBANA made a pilgrimage to all of the ichinomiya shrines in the country between 1675 and 1698, and his journey was documented in total 13 volumes of "Shokoku Ichinomiya Junkeiki" (Pilgrimage Record to the Ichinomiya Shrines). This led to many others making the pilgrimage to the ichinomiya shrines. The 'Zenkoku Ichinomiya Junpai-kai' has now been formed to bring together those undertaking the ichinomiya shrine pilgrimage, and the organization cooperates with the Zenkoku Ichinomiya kai in conducting events to promote the pilgrimage to Ichinomiya Shrines.

A List of ichinomiya shrines

This list includes shrines for which the shrine name contains the title Ichinomiya and those which are widely recognized as such. Those shrines with the same names are also included. The 'Shikinai' column gives the shrine ranking in the Engishiki (procedures of the Engi era) (Myojin or Myojin Taisha), the 'Modern' column gives the shrine ranking under the modern shrine ranking system (kantai kanpei taisha or kokuchu kokuhei chusha), and the 'Beppyo' column specifies whether the shrine is a special list shrine (beppyo jinja).
Shrines in the 'Ichinomiya-kai.'

Shin Ichinomiya Shrines

Established by the Zenkoku Ichinomiya kai