Ichiza no Senji - Ichiza no Senji

...However, no regent was appointed for 40 years after the death of Mototsune and 20 years after the death of Tadahira, and regent politics had not yet been established. However, after Emperor Murakami died and the sickly Emperor Reizei ascended to the throne, and Tadahira's son Saneyori was appointed as regent, it became common to have a regent while the emperor was a child and a regent after he came of age. Furthermore, when Emperor Ichijo's regent Fujiwara no Kaneie resigned as Minister of the Right and received the imperial decree to become the senior position of the Grand Minister of State, the so-called "Ichiza no Senji," the unique and supreme position of the regent was established. Fujiwara no Yorinaga, a nobleman of the late Heian period, wrote in his diary, Daiki, "The regent is in fact the son of emperor, while the chancellor may subject all officials to himself, but he still holds the rank of a vassal," emphasizing the difference between the regent and the chancellor. However, this was merely a formality and ceremonial aspect, and in actual politics, both the regent and the chancellor held real power in leading national affairs.

*Some of the terminology used in reference to "Ichiza Senji" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…ただ基経の没後40年と，忠平の没後20年の間は摂関の任命がなく，まだ摂関政治は定着するに至らなかった。しかし村上天皇が没し，病弱の冷泉天皇が即位して，忠平の男実頼が関白に任ぜられてからは，天皇幼少の間は摂政を，成人の後は関白を置くのが常態となり，さらに一条天皇の摂政藤原兼家が右大臣辞任後，太政大臣の上席たるべき宣旨，いわゆる〈一座宣旨（いちざのせんじ）〉をたまわるに及んで，摂関の独自至上の地位が確立するに至った。　平安後期の公卿藤原頼長はその日記《台記》に，〈摂政はすなわち天子なり，関白は百官を己にすぶるといえども，なお臣の位にあり〉と書いて，摂政と関白との別を強調しているが，それも形式的，儀礼的な面にとどまり，実際政治のうえでは，摂政も関白も国政主導の実権を掌握していたことに変りはない。…

※「一座宣旨」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報