即位そくい
sokui

Noun
Suru Verb

1. accession to the throne; enthronement

Intransitive
エリザベス女王じょおう即位そくいれいねん記念きねんおくられたものみたいです。
erizabesujōono sokui gojūnenno kinenni okurareta monomitaidesu.
It seems it was a gift for the 50th anniversary of Queen Elizabeth's accession to the throne.